Transposable elements (TEs), once considered genomic "junk", are now recognized as critical regulators of genome function and human disease. These mobile genetic elements-including retrotransposons (long interspersed nuclear elements [LINE-1], Alu, short interspersed nuclear element-variable numbers of tandem repeats-Alu [SVA], and human endogenous retrovirus [HERV]) and DNA transposons-are tightly regulated by multilayered mechanisms that operate from transcription through to genomic integration. Although typically silenced in somatic cells, TEs are transiently activated during key developmental stages-such as zygotic genome activation and cell fate determination-where they influence chromatin architecture, transcriptional networks, RNA processing, and innate immune responses. Dysregulation of TEs, however, can lead to genomic instability, chronic inflammation, and various pathologies, including cancer, neurodegeneration, and aging. Paradoxically, their reactivation also presents new opportunities for clinical applications, particularly as diagnostic biomarkers and therapeutic targets. Understanding the dual role of TEs-and balancing their contributions to normal development and disease-is essential for advancing novel therapies and precision medicine.
Humans ; DNA Transposable Elements/physiology* ; Animals ; Long Interspersed Nucleotide Elements/genetics* ; Neoplasms/genetics* ; Genomic Instability/genetics* ; Endogenous Retroviruses/genetics*

Chimeric antigen receptor T (CAR-T) lymphocytes are at the forefront of adoptive immunotherapy research, and this technology has significantly advanced the prospects of tumor immunotherapy. CAR-T therapy has demonstrated remarkable efficacy in haematological tumours of lymphoid origin and provided therapeutic possibility for solid tumours. Currently, CAR-T cell preparation predominantly involves transfection of T cells with viral vectors. However, the production of viral vectors is time-consuming, expensive, and the vectors have low loading capacity, along with insertion instability. Consequently, there is a pressing need to develop more convenient and precise non-viral gene delivery methods. This paper reviews the most promising non-viral gene delivery technologies, including CRISPR/Cas9 gene editing, transposon systems such as Sleeping Beauty (SB) and PiggyBac (PB), and mRNA, and anticipates the future development of non-viral vector-based CAR-T therapies.
Humans ; Immunotherapy, Adoptive/methods* ; Receptors, Chimeric Antigen/immunology* ; Animals ; Gene Transfer Techniques ; Genetic Vectors/genetics* ; Gene Editing ; CRISPR-Cas Systems/genetics* ; DNA Transposable Elements/genetics* ; T-Lymphocytes/immunology* ; Neoplasms/immunology*

To investigate the mechanism of the major capsid protein VP5 (encoded by the UL19 gene) of oncolytic herpes simplex virus type Ⅱ (oHSV2) in regulating the antitumor function of immune cells, we constructed a mouse breast cancer cell line 4T1-iRFP-VP5-GFP stably expressing VP5 protein, near-infrared fluorescent protein (iRFP), and green fluorescent protein (GFP) by using the PiggyBac transposon system. Flow cytometry and Western blotting were employed to screen the monoclonal cell lines expressing both GFP and VP5 and examine the expression stability of UL19 in the constructed cell line. The results of SYBR Green I real-time PCR and Western blotting showed that the copies of UL19 and the expression level of VP5 protein in the 15th passage of 4T1-iRFP-VP5-GFP cells were significantly higher than those in the 4T1 cells transiently transfected with UL19, demonstrating the stable insertion of UL19 into the 4T1 cell genome. The real-time cell analysis (RTCA) was employed to monitor the proliferation of 4T1-iRFP-VP5-GFP cells, which showed similar proliferation activity to their parental 4T1 cells. Further studies confirmed that NK92 cells exhibited stronger cytotoxicity against 4T1-iRFP-VP5-GFP cells than against 4T1 cells. This study layed a foundation for elucidating the role of VP5 protein in regulating immune cells, including T cells and NK cells, via HLA-E in 4T1 cells to exert the anti-tumor function.
Animals ; Mice ; DNA Transposable Elements/genetics* ; Cell Line, Tumor ; Capsid Proteins/biosynthesis* ; Transfection ; Green Fluorescent Proteins/metabolism* ; Oncolytic Viruses/genetics* ; Female ; Simplexvirus/genetics*

PiggyBac is a transposable DNA element originally discovered in the cabbage looper moth (Trichoplusia ni). The T. ni piggyBac transposon can introduce exogenous fragments into a genome, constructing a transgenic organism. Nevertheless, the comprehensive analysis of endogenous piggyBac-like elements (PLEs) is important before using piggyBac, because they may influence the genetic stability of transgenic lines. Herein, we conducted a genome-wide analysis of PLEs in the brown planthopper (BPH) Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), and identified a total of 28 PLE sequences. All N. lugens piggyBac-like elements (NlPLEs) were present as multiple copies in the genome of BPH. Among the identified NlPLEs, NlPLE25 had the highest copy number and it was distributed on five chromosomes. The full length of NlPLE25 consisted of terminal inverted repeats and sub-terminal inverted repeats at both terminals, as well as a single open reading frame transposase encoding 546 amino acids. Furthermore, NlPLE25 transposase caused precise excision and transposition in cultured insect cells and also restored the original TTAA target sequence after excision. A cross-recognition between the NlPLE25 transposon and the piggyBac transposon was also revealed in this study. These findings provide useful information for the construction of transgenic insect lines.
Amino Acid Sequence ; Animals ; Animals, Genetically Modified ; DNA Transposable Elements/genetics* ; Hemiptera/genetics* ; Transposases/genetics*

A new wave of research has been inspired by the CRISPR-Cas system with respect to their application in genome editing. The CRISPR-Cas system can not only be applied in gene knockout and insertion, but also be used in base editing, transcriptional regulation and recombination of gene clusters. However, the low efficiency of homology-directed repair (HDR) limits its application. Unlike the CRISPR-Cas system, mobile genetic elements (MGE) can insert DNA fragments into cell chromosomes without the aid of HDR. Recently, it is reported that CRISPR-related transposable elements can guide targeted DNA insertion. Their transposition mechanisms and reprogramming abilities have brought novel opportunities to the development of this field. This review summarized the research progress and application development of natural CRISPR-related transposable elements in recent years, as well as the applications of fused dCas9-transposase. It proposed the application prospects and potential challenges of CRISPR-related transposable elements in the future, which provided a reference for the development direction of gene editing tools.
DNA Transposable Elements/genetics* ; Gene Editing ; CRISPR-Cas Systems/genetics*

Adenosine/metabolism* ; Animals ; Chromatin/metabolism* ; DNA Transposable Elements ; Epigenesis, Genetic ; RNA, Messenger/metabolism*

Mammalian fertilization begins with the fusion of two specialized gametes, followed by major epigenetic remodeling leading to the formation of a totipotent embryo. During the development of the pre-implantation embryo, precise reprogramming progress is a prerequisite for avoiding developmental defects or embryonic lethality, but the underlying molecular mechanisms remain elusive. For the past few years, unprecedented breakthroughs have been made in mapping the regulatory network of dynamic epigenomes during mammalian early embryo development, taking advantage of multiple advances and innovations in low-input genome-wide chromatin analysis technologies. The aim of this review is to highlight the most recent progress in understanding the mechanisms of epigenetic remodeling during early embryogenesis in mammals, including DNA methylation, histone modifications, chromatin accessibility and 3D chromatin organization.
Animals ; Chromatin Assembly and Disassembly ; DNA Methylation ; DNA Transposable Elements ; Embryo, Mammalian ; Embryonic Development/genetics* ; Epigenesis, Genetic ; Epigenome ; Female ; Fertilization/physiology* ; Gene Expression Regulation, Developmental ; Histone Code ; Histones/metabolism* ; Male ; Mice ; Oocytes/metabolism* ; Spermatozoa/metabolism*

Ralstonia solanacearum strain PRS-84 used in this study was isolated from diseased Pogostemon cablin plants in our previous study.The competent cells of R.solanacearum strain PRS-84 were transformed by electroporation with Tn5 transposon and then were plated on TTC agar plates containing kanamycin to select for kanamycin-resistant colonies.The detection of kanamycin-resistant gene in kanamycin-resistant colonies was performed by PCR.Further,the flanking fragments of Tn5 transposon insertion site in the mutants were amplified by inverse PCR,and the flanking fragments were sequenced and analyzed.The results indicated that the kanamycin-resistant colonies were obtained in the transformation experiment of R.solanacearum strain PRS-84 by electroporation with Tn5 transposon.A specific band of approximately 700 bp was amplified by PCR from kanamycin-resistant colonies.The flanking sequences of Tn5 transposon insertion site in the transformants were obtained by inverse PCR.After sequencing and sequence analysis of Tn5 transposon insertion site in mutants,we preliminarily speculated that the Tn5 transposon inserted in the typ A gene,rec O gene and gid A gene in three mutants,respectively.A random mutagenesis system of R.solanacearum strain PRS-84 by electroporation with Tn5 transposon has been established,and the Tn5 insertion mutants have been obtained.This study might facilitate the creation of mutant library and the discovery of the virulence gene of R.solanacearum isolated from P.cablin.
DNA Transposable Elements ; Electroporation ; Genes, Bacterial ; Mutagenesis, Insertional ; Pogostemon ; microbiology ; Ralstonia solanacearum ; genetics ; Virulence

Animals ; Cellular Reprogramming ; genetics ; DNA Transposable Elements ; genetics ; Genetic Vectors ; genetics ; Genome ; genetics ; Humans ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; Mutagenesis

Transposable elements are one of major sources to cause genomic instability through various mechanisms including de novo insertion, insertion-mediated genomic deletion, and recombination-associated genomic deletion. Among them is Alu element which is the most abundant element, composing ~10% of the human genome. The element emerged in the primate genome 65 million years ago and has since propagated successfully in the human and non-human primate genomes. Alu element is a non-autonomous retrotransposon and therefore retrotransposed using L1-enzyme machinery. The 'master gene' model has been generally accepted to explain Alu element amplification in primate genomes. According to the model, different subfamilies of Alu elements are created by mutations on the master gene and most Alu elements are amplified from the hyperactive master genes. Alu element is frequently involved in genomic rearrangements in the human genome due to its abundance and sequence identity between them. The genomic rearrangements caused by Alu elements could lead to genetic disorders such as hereditary disease, blood disorder, and neurological disorder. In fact, Alu elements are associated with approximately 0.1% of human genetic disorders. The first part of this review discusses mechanisms of Alu amplification and diversity among different Alu subfamilies. The second part discusses the particular role of Alu elements in generating genomic rearrangements as well as human genetic disorders.
Alu Elements* ; DNA Transposable Elements ; Genetic Diseases, Inborn ; Genome ; Genome, Human ; Genomic Instability ; Humans* ; Nervous System Diseases ; Primates ; Recombination, Genetic ; Retroelements