PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “CRISPR knockout”

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 55 records · Page 3Linked to original sources

CRISPR/Cas9-Mediated Gene-Knockout and In Situ Complementation System for Phytophthora sojae.

The establishment of reliable and efficient systems for genome editing in Phytophthora is very important for studying gene functions. Here, step-by-step methods for CRISPR/Cas9-based gene knockout and in situ complementation for Phytophthora sojae are presented. These steps include the sgRNA design, Cas9-sgRNA plasmid construction, homologous replacement, complementation vector construction, P. sojae transformation, and detection of mutations for both gene knockout and in situ complementation. These methods may also potentially be adapted for other Phytophthora species.

Phytophthora↗

Protocol for robust gene knockout and reliable validation in human cell lines using quad-guide RNA vectors.

CRISPR-Cas9 is a powerful tool for editing genomic loci, however achieving high knockout efficiency at certain targets remains challenging. Here, we present a protocol for gene knockout using an all-in-one, quad-guide RNA-expressing vector. We describe steps for plasmid construction, virus preparation, transduction, and subsequent gene editing and functional validation within DLD-1 colorectal adenocarcinoma cells. This strategy provides an efficient workflow for gene knockout that is rapidly confirmed through PCR amplification of mRNA derived from the targeted gene loci.

Biotechnology and bioengineering↗

Development and Characterization of an Inducible Bacterial Artificial Chromosome System for Studying Lytic Replication and Pathogenesis of Kaposi's Sarcoma-Associated Herpesvirus.

Bacterial artificial chromosome (BAC) is widely used to manipulate herpesvirus genome and generate recombinant virus. Here, we developed a new KSHV BACmid, namely as iBAC, by replacing the EGFP with TET3G transactivator under EF1α promoter and inserted Tet response elements in the promoter of RTA in the original KSHV BAC16 clone and characterized KSHV lytic replication in SLK-iBAC cells. SLK-iBAC cells developed more efficient lytic replication and generated more progeny virus than iSLK-BAC16 cells upon the same conditions of doxycycline treatment. Since SLK-iBAC cells only occupied hygromycin selection marker, it is convenient to generate cellular gene knockout via lentivirus-mediated CRISPR-Cas9 or stably express viral or cellular gene via lentivirus followed by antibiotic selection, making iBAC system a better tool to identify cellular targets of viral proteins in the context of virus infection or study the role of viral or cellular genes for KSHV lytic replication and pathogenesis. In addition, iBAC is color-free and can be utilized to track subcellular localization of viral proteins or colocalization between different viral proteins by introducing fusing fluorescent proteins into the BAC backbone. Therefore, the new KSHV iBAC is a powerful inducible tool to study KSHV lytic replication and pathogenesis in cell model.

Chromosomes, Artificial, Bacterial↗

Towards a CRISPeR understanding of homologous recombination with high-throughput functional genomics.

CRISPR-dependent genome editing enables the study of genes and mutations on a large scale. Here we review CRISPR-based functional genomics technologies that generate gene knockouts and single nucleotide variants (SNVs) and discuss how their use has provided new important insights into the function of homologous recombination (HR) genes. In particular, we highlight discoveries from CRISPR screens that have contributed to define the response to PARP inhibition in cells deficient for the HR genes BRCA1 and BRCA2, uncover genes whose loss causes synthetic lethality in combination with BRCA1/2 deficiency, and characterize the function of BRCA1/2 SNVs of uncertain clinical significance. Further use of these approaches, combined with next-generation CRISPR-based technologies, will aid to dissect the genetic network of the HR pathway, define the impact of HR mutations on cancer etiology and treatment, and develop novel targeted therapies for HR-deficient tumors.

Gene Regulatory Networks↗

The emerging impact of CRISPR and gene editing on global crop improvement.

The advent of CRISPR-based genome editing has revolutionized crop improvement, offering unprecedented precision and efficiency in modifying key agronomic traits. This review comprehensively examines the mechanisms, applications, and future potential of CRISPR technology in enhancing global crop production. CRISPR-Cas systems, originally identified as adaptive immune mechanisms in bacteria and archaea, have been repurposed for targeted genome editing in plants. The CRISPR-Cas9 system, in particular, has emerged as a powerful tool for introducing site-specific double-strand breaks, enabling precise genetic modifications. The three-stage process of adaptation, expression, and interference underlies the CRISPR mechanism, with guide RNAs directing Cas endonucleases to specific genomic loci. Advances in CRISPR technology have expanded its applications beyond gene knockouts, encompassing base editing, prime editing, and epigenome editing. These innovations have facilitated the development of crops with enhanced yield, stress tolerance, disease resistance, nutritional content, and post-harvest quality. However, challenges related to off-target effects, regulatory hurdles, ethical concerns, and public acceptance must be addressed to fully harness the potential of CRISPR in agriculture. Integration of CRISPR with other cutting-edge technologies, such as synthetic biology, artificial intelligence, and high-throughput phenotyping, holds immense promise for accelerating crop improvement efforts. As research continues to refine CRISPR tools and expand their applicability across diverse plant species, this transformative technology is poised to play a pivotal role in shaping a sustainable, resilient, and productive global food system for future generations.

Gene Editing↗

Evaluation of germline transmission of electroporation-mediated double gene-edited cattle lines.

Gene editing in livestock using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) offers a promising approach for genetic improvement in cattle. This study evaluated germline transmission and mutation stability of double-knockout cattle generated by zygote electroporation. Previously reported myostatin/beta-lactoglobulin (MSTN/BLG) and newly generated α-1,3-galactosyltransferase (GGTA1/BLG) double-knockout cattle were produced using CRISPR/Cas9-mediated genome editing. Targeted deep sequencing demonstrated extensive somatic mosaicism across multiple tissues. Computer-assisted sperm analysis (CASA) demonstrated normal sperm motility in MSTN/BLG double-knockout males. Fertilization of wild-type oocytes produced heterozygous embryos, with mutation frequencies of 37.76 ± 10.74% at the MSTN locus and 54.80 ± 7.73% at the BLG locus, as assessed by T7 endonuclease I (T7E1) assay. MSTN/BLG double-knockout sperm were subsequently used for embryo production and for artificial insemination of GGTA1/BLG double-knockout females. Healthy offspring were successfully obtained (n = 3), alongside one stillborn calf. Targeted deep sequencing of all four progenies revealed highly variable allele frequencies that deviated substantially from the approximately 50% expected for heterozygous germline transmission. In contrast, whole-genome sequencing (WGS) results were consistent with Mendelian expectations, underscoring the limitations of PCR-based targeted sequencing for assessing germline transmission in mosaic founders. These results show that CRISPR/Cas9-edited embryos generated by electroporation can develop into healthy, sexually mature cattle capable of germline transmission. While variable transmission rates were observed owing to founder mosaicism, non-mosaic F1 offspring were successfully generated. However, direct, embryo-mediated gene-editing strategies remain technically and economically challenging for large-scale commercial calf production, and reports in cattle are limited. This study provides a reference for future applications of gene-edited embryos and their germline propagation.

Animals↗

Targeted multiplex gene knockouts in Lemna minor using CRISPR/Cas9.

Lemna minor (commonly known as duckweed) is a fast-growing aquatic plant recognized as a promising green bioreactor for recombinant protein production. Its rapid proliferation, high protein yield, environmental adaptability, and edibility make it highly attractive for biotechnological applications. It is essential to develop and expand genetic tools tailored to this species to maximize these advantages and further unlock its biotechnological potential. A key strategy for achieving this goal is the implementation of advanced genome editing technologies, such as the CRISPR/Cas9 system. Although multiplex CRISPR/Cas9 gene editing has previously been successfully applied in Lemna aequinoctialis, the capability of the endogenous plant tRNA processing system for multiplex editing in L. minor using the polycistronic tRNA-sgRNA (PTG)/Cas9 system has not yet been explored. In this study, a PTG construct was engineered to include four sgRNAs designed to simultaneously target two plant-specific glycosyltransferase genes: α-1,3-fucosyltransferase (FucT) and β-1,2-xylosyltransferase (XylT). As anticipated, the PTG-Cas9 system successfully induced frameshift mutations, characterized by insertions and deletions (indels), in regenerated L. minor plants derived from transformed calli. Validation via PCR and RT-PCR analysis, followed by sequencing of the target loci, confirmed the presence of indels at the target sites. Furthermore, western blot analyses utilizing antibodies specific to XylT and FucT in two homozygous lines (lines 44 and 217) revealed truncated XylT proteins in both lines. Moreover, an in-frame FucT protein was detected in line 217, whereas FucT expression was absent in line 44. This study marked the first successful demonstration of PTG-Cas9 system for multiplex genome editing in L. minor, paving the way for advanced genetic engineering in this species.

CRISPR-Cas Systems↗

CRISPR tools for T cells: targeting the genome, epigenome, and transcriptome.

T cell therapy has curative potential for many cancers. Despite impressive clinical efficacy in hematological malignancies, current T cell therapy still faces challenges related to sustaining responses, antigen escape, cytotoxicity, limited accessibility, and difficulties in treating solid tumors. The advent of CRISPR (clustered regularly interspaced short palindromic repeats) technologies provides a promising solution to these challenges. CRISPR technologies have grown from merely tools for gene knockout to sophisticated tools that can engineer cells at various levels of the genome, epigenome, and transcriptome. In this review we discuss recent technological advancements and how their application to T cells has the potential to steer the next generation of cellular therapy. We highlight emerging applications and current technological limitations that future tool development aims to overcome.

Humans↗

SelectRepair Knockout: Efficient PTC-Free Gene Knockout Through Selectable Homology-Directed DNA Repair.

Generating nonessential gene knockouts using CRISPR/Cas9 technology is becoming increasingly common in biological research. In a typical workflow, the Cas9 endonuclease is used to induce a DNA double-strand break that relies on nonhomologous end-joining (NHEJ) to introduce a premature termination codon (PTC) in the target gene. The goal is to isolate clones in which the gene produces PTC-containing mRNA transcripts that are degraded via nonsense-mediated mRNA decay (NMD) to cause loss of gene function. Unfortunately, this approach is laborious, and not all PTCs trigger NMD. More importantly, mounting evidence suggest that PTC mutations can also result in a transcriptional adaptation response that can mask the effects of a PTC-mediated gene knockout. In this chapter, we present a PTC-free gene knockout strategy that implements homology-directed DNA repair (HDR) with selectable markers to substantially reduce the complexity of the screening and validation of genome edits in cells containing more than one gene copy as in the case of the commonly used hypotriploid HEK293 cell line. We describe how to obtain a complete knockout of the Ligase IV protein (LIG4) and provide considerations for the application of this SelectRepair Knockout method to other genes.

Humans↗

CRISPR/Cas in gynecologic cancers: A review of experimental and therapeutic applications.

Gynecological malignancies-including cervical, ovarian, and endometrial cancers-remain a major global health challenge, contributing significantly to cancer-related morbidity and mortality among women. Despite advances in conventional treatments such as surgery, chemotherapy, radiotherapy, and immunotherapy, issues such as drug resistance, tumor recurrence, and limited efficacy in advanced-stage disease necessitate novel therapeutic strategies. The emergence of CRISPR/Cas-based genome editing has revolutionized cancer research by enabling precise, efficient, and programmable modifications of specific genomic loci. In gynecologic oncology, CRISPR/Cas systems have been employed to dissect oncogenic mechanisms, identify therapeutic targets, and develop innovative treatment modalities. In cervical cancer, CRISPR-mediated targeting of HPV E6 and E7 oncogenes has shown potential in restoring tumor suppressor pathways and enhancing chemosensitivity. In ovarian cancer, gene editing has been used to modulate chemoresistance, tumor angiogenesis, and metastasis through the knockout of key regulators such as DNMT1, EGFL6, and BRCA1/2. Similarly, in endometrial cancer, CRISPR tools have elucidated mechanisms of hormonal resistance and facilitated the development of in vivo models via somatic gene editing. This review highlights recent advances in the application of CRISPR/Cas technology to gynecologic malignancies, discussing its potential as both a therapeutic and research platform while acknowledging current limitations and translational hurdles.

Humans↗

An in vivo barcoded CRISPR-Cas9 screen identifies Ncoa4-mediated ferritinophagy as a dependence in Tet2-deficient hematopoiesis.

TET2 is among the most commonly mutated genes in both clonal hematopoiesis and myeloid malignancies; thus, the ability to identify selective dependencies in TET2-deficient cells has broad translational significance. Here, we identify regulators of Tet2 knockout (KO) hematopoietic stem and progenitor cell (HSPC) expansion using an in vivo CRISPR-Cas9 KO screen, in which nucleotide barcoding enabled large-scale clonal tracing of Tet2-deficient HSPCs in a physiologic setting. Our screen identified candidate genes, including Ncoa4, that are selectively required for Tet2 KO clonal outgrowth compared with wild type. Ncoa4 targets ferritin for lysosomal degradation (ferritinophagy), maintaining intracellular iron homeostasis by releasing labile iron in response to cellular demands. In Tet2-deficient HSPCs, increased mitochondrial adenosine triphosphate production correlates with increased cellular iron requirements and, in turn, promotes Ncoa4-dependent ferritinophagy. Restricting iron availability reduces Tet2 KO stem cell numbers, revealing a dependency in TET2-mutated myeloid neoplasms.

CRISPR-Cas Systems↗

A dual-dimensional CRISPR toolkit enables one-step high-efficiency multiplex genome editing in Komagataella phaffii.

Against the backdrop of green biomanufacturing, engineering methanol-utilizing Komagataella phaffii (K. phaffii) represents an effective strategy to expand the one carbon (C1) product profile and speed up the industrialization of C1-based bioeconomy. To address the technical challenges of low efficiency and cumbersome experimental procedures for multiplex gene editing and precise large-fragment integration during the reconstruction of complex metabolic pathways in K. phaffii, this study established a CRISPR toolkit - Efficient Multi-Gene Editing System 3.0 (EMGES 3.0) - which enabled one-step large-fragment integration coupled with multiplex gene knockout. EMGES 3.0 was constructed through the synergistic optimization of a repair-engineered chassis and an episomal CRISPR vector. For chassis engineering, five DNA repair modules: Δlig4 (DNA Ligase IV, non-homologous end joining end ligation), ppMRE11(The endogenous MRE11 gene from Pichia pastoris) overexpression (The Meiotic Recombination 11, DNA double-strand break end resection), Δrad9 (Radiation-Sensitive 9, DNA damage checkpoint regulation), Δmph1 (Mutator Phenotype Helicase 1, improvement of homologous recombinant strand extension), and PapRecT-PaSSB co-expression (stabilization of recombination intermediates) were integrated to generate the highly recombinogenic strain Y09. For vector engineering, cenARS was replaced by panARS and the endogenous promoter PGAP was employed to drive the double hammerhead ribozyme-single guide RNA-hepatitis delta virus ribozyme (double HH-sgRNA-HDV: dHgH)-mediated sgRNA expression, yielding the optimized vector Nov_pGAP_panARS_pLAT1_Cas9. These two features on K. phaffii together enhanced the EMGES 3.0 to a higher standard of transformation rate and editing efficiency. According to our results, EMGES 3.0 achieved dual-functional gene knockout efficiencies between 76.6% and 100%. For insertion of medium-long fragments (>4.5 kb), the efficiency achieved 93.3%. In addition, the one-step integration of ultra-long fragments (>16 kb) achieved 14.8%, which was reported for the first time. Furthermore, the efficiency of simultaneous long-fragment integration at three neutral loci reached 38.4% (>15 kb). We applied the system for one-step production of free fatty acids (FFAs, yield: 5.82 ∼ 7.30 mg/L/OD600) and resveratrol (yield: 1.14 ∼ 1.28 mg/L) using methanol as the sole carbon source. EMGES 3.0 provides a robust technical foundation for complex compounds biosynthesis and high-yield industrial strains, while also advancing K. phaffii as an industrial synthetic biology chassis for efficient C1 utilization.

CRISPR-Cas Systems↗

A statistical simulation model to guide the choices of analytical methods in arrayed CRISPR screen experiments.

An arrayed CRISPR screen is a high-throughput functional genomic screening method, which typically uses 384 well plates and has different gene knockouts in different wells. Despite various computational workflows, there is currently no systematic way to find what is a good workflow for arrayed CRISPR screening data analysis. To guide this choice, we developed a statistical simulation model that mimics the data generating process of arrayed CRISPR screening experiments. Our model is flexible and can simulate effects on phenotypic readouts of various experimental factors, such as the effect size of gene editing, as well as biological and technical variations. With two examples, we showed that the simulation model can assist making principled choice of normalization and hit calling method for the arrayed CRISPR data analysis. This simulation model is implemented in an R package and can be downloaded from Github.

CRISPR-Cas Systems↗

Clinical translation of senescence-related pan-cancer multi-omics: tools for assessment and immunotherapy prediction.

Cellular senescence (CS) exerts dual roles in tumorigenesis, yet its pan-cancer molecular characteristics and clinical value remain unclear, hindering its translation to oncology and personalized therapy. To address the lack of specific and universal tools for senescence assessment and immunotherapy response prediction, this study systematically analyzed 1259 CS-related genes from the CellAge database across 31 cancer types by integrating multi-omics data, including bulk RNA-seq, single-cell/spatial transcriptomics, and CRISPR screening. We developed a rank-based algorithm SenScoreR (publicly available at https://gxhub.shinyapps.io/SenScoreR/ ) for senescence quantification, validated with 10 independent datasets, and constructed a machine learning-based predictive model CS.Sig for immunotherapy response. Results showed that tumors had significantly lower Rank-based Senescence Score (RSS) than normal tissues across 31 cancers (average diagnostic AUC = 0.895), with low RSS linked to poor survival; high RSS correlated with reduced genomic instability, enriched CD8⁺ T/NK cell/macrophage infiltration, upregulated PD-L1 expression, and elevated immune cytolytic activity. CS.Sig demonstrated robust performance in predicting ICI response (AUC = 0.716 across 10 cohorts), outperforming 13 existing signatures, while CRISPR screening identified 17 senescence-related targets (e.g., CEP55, PPP1CC) whose knockout enhanced anti-tumor immunity. Our findings clarify CS's role in maintaining tumor genomic stability and shaping immune microenvironments, and the developed SenScoreR, CS.Sig, and identified targets bridge basic CS research with clinical oncology, providing a translational resource and hypothesis basis for future experimental and clinical validation.

Journal Article↗

Directing fratricide within T cell products using an anti-uPAR chimeric antigen receptor to drive the production of potent therapeutic cells.

Cell therapy manufacturing of primary T cells often results in heterogeneous cell populations in the final product, with many cells lacking desired receptor expression or exhausted and other dysfunctional phenotypes. Here, we design a novel cell-intrinsic strategy to genetically reprogram primary human T cells to autonomously detect and eliminate dysfunctional cells. This integrated detection and elimination process, known as directed fratricide, is programmed via non-viral CRISPR genome editing to eliminate the T cell receptor (TCR) alpha chain (TRAC gene knockout) and integrate a chimeric antigen receptor (CAR) against the urokinase-type plasminogen activator receptor (uPAR), also known as CD87. In these cell products, strong T cell stimulation or activation during manufacturing causes a small subset of cells to express uPAR, which triggers CAR-mediated killing within the product. This fratricide induces proliferation in the desired cells and destroys undesired cells, a process that could be modeled computationally and controlled robustly via supplements to the culture media. The strategy enabled enrichment of anti-uPAR and anti-disialoganglioside (GD2) CAR-T cell products up to ≥99% CAR+/TCR-, favoring a memory-like phenotype. Understanding growth dynamics among T cell subsets and reprogramming them via CRISPR could accelerate the biomanufacturing of potent cell products without extensive selection methods.

Humans↗

CRISPR/Cpf1-mediated knockout of FLG in human induced pluripotent stem cells generates a model for studying epidermal barrier dysfunction.

Loss of filaggrin (FLG) function impairs skin barrier formation and contributes to common inflammatory skin diseases. In this study, we established a FLG knockout human induced pluripotent stem cell (iPSC) line based on KOLF2.1 J using CRISPR/Cas12a (Cpf1)-mediated genome editing. A guide RNA targeting exon 2 introduced a homozygous mutation, which was confirmed by sequencing. The edited cells maintained typical pluripotent stem cell morphology, expressed key undifferentiated markers, and retained the ability to differentiate into all three germ layers. Karyotype and copy number variation (CNV) analyses confirmed genomic stability and parental origin; the cells were free of mycoplasma. This cell line enables studies of FLG-associated skin biology and pathology.

Humans↗

Comprehensive transcriptomic analysis of myostatin-knockout pigs: insights into muscle growth and lipid metabolism.

Pigs are a vital source of protein worldwide, contributing approximately 43% of global meat production. Recent genetic advancements in the myostatin (MSTN) gene have facilitated the development of double-muscling traits in livestock. In this study, we investigate the transcriptomic profiles of second-generation MSTN-knockout (MSTN-/-) pigs, generated through CRISPR/Cas9 gene editing and somatic cell nuclear transfer (SCNT). Using RNA sequencing, we compared the transcriptomic landscapes of muscle tissues from MSTN-/- pigs and wild-type (WT) counterparts. The sequencing yielded an average unique read mapping rate of 86.7% to the Sus scrofa reference genome. Our analysis revealed 15,142 differentially expressed genes (DEGs), including 121 novel genes, with 2554 genes upregulated and 1629 downregulated in the MSTN-/- group relative to the wild-type group. Notable transcriptomic changes were identified in genes associated with muscle development, lipid metabolism, and other physiological processes. These findings provide valuable insights into the molecular consequences of MSTN inactivation, with potential applications in the optimization of livestock breeding and advancements in biomedical research.

Animals↗

Systematic discovery of CRISPR-boosted CAR T cell immunotherapies.

Chimeric antigen receptor (CAR) T cell therapy has shown remarkable success in treating blood cancers, but CAR T cell dysfunction remains a common cause of treatment failure1. Here we present CELLFIE, a CRISPR screening platform for enhancing CAR T cells across multiple clinical objectives. We performed genome-wide screens in human primary CAR T cells, with readouts capturing key aspects of T cell biology, including proliferation, target cell recognition, activation, apoptosis and fratricide, and exhaustion. Screening hits were prioritized using a new in vivo CROP-seq2 method in a xenograft model of human leukaemia, establishing several gene knockouts that boost CAR T cell efficacy. Most notably, we discovered that RHOG knockout is a potent and unexpected CAR T cell enhancer, both individually and together with FAS knockout, which was validated across multiple in vivo models, CAR designs and sample donors, and in patient-derived cells. Demonstrating the versatility of the CELLFIE platform, we also conducted combinatorial CRISPR screens to identify synergistic gene pairs and saturation base-editing screens to characterize RHOG variants. In summary, we discovered, validated and biologically characterized CRISPR-boosted CAR T cells that outperform standard CAR T cells in widely used benchmarks, establishing a foundational resource for optimizing cell-based immunotherapies.

Humans↗