LINE-1 ORF1p is a Promising Biomarker in Cervical Intraepithelial Neoplasia Degree Assessment.

Cervical intraepithelial neoplasia (CIN) represents a spectrum of preinvasive squamous lesions within the cervical epithelium, whose identification is a diagnostic challenge due to subtle histomorphological differences among its categories. This study explores ORF1p, a nucleic acid-binding protein derived from long interspersed nuclear element-1 (LINE-1), as a potential biomarker for enhancing CIN diagnosis. A comprehensive analysis of 143 cervical specimens, encompassing CIN I (n=20), CIN II (n=46), CIN III (n=14), invasive cancer (n=32), and nondysplastic cases (normal cervical epithelia (n=24) and atrophy (n=7) were conducted. ORF1p, Ki67, and p16 expressions were evaluated using immunohistochemistry. ORF1p immunopositivity was detected in the vast majority [110/112 (98.2%)] of dysplastic and neoplastic (CIN and invasive cancer) specimens, whereas 19/24 (79.2%) of normal cervical specimens lacked ORF1p expression. The observed pattern of ORF1p expression showed a progressively increasing extent and intensity with advancing CIN grades. CIN I exhibited mild ORF1p expression in the lower one or two-thirds of the cervical epithelium [14/16 (87.5%)], whereas CIN II demonstrated moderate to strong ORF1p expression spanning the lower two-thirds [29/46 (63.0%)]. Pronounced transepithelial ORF1p immunopositivity characterized CIN III cases [13/14 (92.8%)] and cervical cancer [30/32 (93.8%)]. These findings propose ORF1p as a valuable indicator even for detecting CIN I, effectively discerning them from normal cervical tissue (p < 0.0001). Our findings underscore the potential of ORF1p as an early diagnostic marker for cervical neoplasia.

Prolonged activity of the transposase helper may raise safety concerns during DNA transposon-based gene therapy.

DNA transposon-based gene delivery vectors represent a promising new branch of randomly integrating vector development for gene therapy. For the side-by-side evaluation of the piggyBac and Sleeping Beauty systems-the only DNA transposons currently employed in clinical trials-during therapeutic intervention, we treated the mouse model of tyrosinemia type I with liver-targeted gene delivery using both transposon vectors. For genome-wide mapping of transposon insertion sites we developed a new next-generation sequencing procedure called streptavidin-based enrichment sequencing, which allowed us to identify approximately one million integration sites for both systems. We revealed that a high proportion of piggyBac integrations are clustered in hot regions and found that they are frequently recurring at the same genomic positions among treated animals, indicating that the genome-wide distribution of Sleeping Beauty-generated integrations is closer to random. We also revealed that the piggyBac transposase protein exhibits prolonged activity, which predicts the risk of oncogenesis by generating chromosomal double-strand breaks. Safety concerns associated with prolonged transpositional activity draw attention to the importance of squeezing the active state of the transposase enzymes into a narrower time window.

A versatile transposon-based technology to generate loss- and gain-of-function phenotypes in the mouse liver.

BACKGROUND: Understanding the contribution of gene function in distinct organ systems to the pathogenesis of human diseases in biomedical research requires modifying gene expression through the generation of gain- and loss-of-function phenotypes in model organisms, for instance, the mouse. However, methods to modify both germline and somatic genomes have important limitations that prevent easy, strong, and stable expression of transgenes. For instance, while the liver is remarkably easy to target, nucleic acids introduced to modify the genome of hepatocytes are rapidly lost, or the transgene expression they mediate becomes inhibited due to the action of effector pathways for the elimination of exogenous DNA. Novel methods are required to overcome these challenges, and here we develop a somatic gene delivery technology enabling long-lasting high-level transgene expression in the entire hepatocyte population of mice. RESULTS: We exploit the fumarylacetoacetate hydrolase (Fah) gene correction-induced regeneration in Fah-deficient livers, to demonstrate that such approach stabilizes luciferase expression more than 5000-fold above the level detected in WT animals, following plasmid DNA introduction complemented by transposon-mediated chromosomal gene transfer. Building on this advancement, we created a versatile technology platform for performing gene function analysis in vivo in the mouse liver. Our technology allows the tag-free expression of proteins of interest and silencing of any arbitrary gene in the mouse genome. This was achieved by applying the HADHA/B endogenous bidirectional promoter capable of driving well-balanced bidirectional expression and by optimizing in vivo intronic artificial microRNA-based gene silencing. We demonstrated the particular usefulness of the technology in cancer research by creating a p53-silenced and hRas G12V-overexpressing tumor model. CONCLUSIONS: We developed a versatile technology platform for in vivo somatic genome editing in the mouse liver, which meets multiple requirements for long-lasting high-level transgene expression. We believe that this technology will contribute to the development of a more accurate new generation of tools for gene function analysis in mice.