{"id":2754,"date":"2026-08-28T11:00:00","date_gmt":"2026-08-28T15:00:00","guid":{"rendered":"https:\/\/www.insilens.com\/?p=2754"},"modified":"2026-08-28T16:38:11","modified_gmt":"2026-08-28T20:38:11","slug":"prime-assembly-enables-large-dsb-free-dna-integration","status":"publish","type":"post","link":"https:\/\/www.insilens.com\/?p=2754","title":{"rendered":"Prime Assembly Enables Large, DSB-Free DNA Integration"},"content":{"rendered":"

Institution:<\/strong> Seoul National University · Technology:<\/strong> Prime Assembly · Publication:<\/strong> Nature Biotechnology · Application:<\/strong> Large DNA Integration Without Double-Strand Breaks · Date:<\/strong> August 28, 2026<\/p>\n

\"20260828_Seoul_National_University_Prime_Assembly_Technology_and_Modalities\"<\/p>\n

Summary<\/h4>\n

Seoul National University researchers published a prime-editing-derived DNA assembly system in Nature Biotechnology that enables kilobase-scale gene insertion and megabase-scale excision without generating double-strand breaks, demonstrating functional CD19 CAR-T cell engineering as a proof-of-concept application.<\/p>\n

What Happened<\/h4>\n

The flap-annealing, prime-editing-derived system achieved up to 57.8% replacement efficiency with a 2.9kb donor sequence in HEK293T cells. CD19 CAR insertion in primary T cells reached up to 28.1%, with functional antitumor activity demonstrated in xenograft models. Off-target editing was measured below 0.06%. In vivo testing used hydrodynamic mouse-liver delivery, a method not clinically translatable, and achieved 4.3% and 1.1% insertion in GFP-positive hepatocytes across two conditions.<\/p>\n

Deep Analysis<\/h4>\n

Avoiding double-strand breaks is a significant potential safety advantage over CRISPR-Cas9-based large-fragment knock-in approaches, which carry translocation and large-deletion risks. The 28.1% CD19 CAR insertion efficiency in primary T cells with demonstrated functional antitumor activity in xenograft models is the most clinically relevant data point, suggesting potential applicability to cell-therapy manufacturing. However, the in vivo liver delivery data relied on a non-clinically-translatable hydrodynamic injection method, meaning a viable in vivo delivery vehicle for non-cell-therapy applications has not yet been demonstrated. The sub-0.06% off-target rate is a favorable early specificity signal, though it was measured in a research setting rather than under clinical validation standards.<\/p>\n

Company and Product Background<\/h4>\n

This is academic, publication-stage gene-editing technology not yet licensed to or developed by a disclosed company. Prime editing-derived tools sit alongside CRISPR-Cas9, base editing, and other precision genome-engineering platforms being pursued for both ex vivo cell therapy and in vivo gene therapy applications.<\/p>\n

Signal Extraction<\/h4>\n\n\n\n\n\n\n\n
Factor<\/th>\nAssessment<\/th>\n<\/tr>\n
Efficiency<\/td>\nUp to 57.8% replacement (2.9kb donor, HEK293T cells)<\/td>\n<\/tr>\n
Cell Therapy Application<\/td>\nCD19 CAR insertion up to 28.1% in primary T cells, functional in xenograft model<\/td>\n<\/tr>\n
Specificity<\/td>\nOff-target editing below 0.06%<\/td>\n<\/tr>\n
In Vivo Delivery<\/td>\nHydrodynamic mouse-liver injection (research-only method) gave 4.3%\/1.1% insertion<\/td>\n<\/tr>\n
Signal Type<\/td>\nAcademic publication, platform technology demonstration<\/td>\n<\/tr>\n<\/table>\n

Reading the Signal<\/h4>\n

Bull case:<\/strong> A double-strand-break-free method achieving nearly 30% functional CAR insertion in primary T cells, with sub-0.06% off-target rates, addresses two of the biggest safety concerns in large-fragment genome engineering and could meaningfully derisk next-generation cell-therapy manufacturing.<\/p>\n

Bear case:<\/strong> The in vivo delivery data relied on a hydrodynamic injection method with no clinical translatability, meaning the platform’s applicability beyond ex vivo cell engineering remains unproven, and academic proof-of-concept efficiency numbers frequently decline when methods are optimized for GMP-compatible clinical manufacturing.<\/p>\n

InSilens Take<\/h4>\n

The ex vivo CD19 CAR-T data are the most credible near-term signal here, a DSB-free approach with meaningful insertion efficiency and functional activity is a genuine tool for cell-therapy developers, even though in vivo applications remain a much earlier-stage and unresolved delivery problem.<\/p>\n

Signal Assessment<\/h4>\n

Importance:<\/strong> 4\/5 · Direction:<\/strong> Uncertain · Confidence:<\/strong> High on facts, Low on interpretation<\/p>\n","protected":false},"excerpt":{"rendered":"

Seoul National University researchers published a prime-editing-derived DNA assembly system in Nature Biotechnology that enables kilobase-scale gene insertion and megabase-scale excision without generating double-strand breaks, demonstrating functional CD19 CAR-T cell engineering as a proof-of-concept…<\/p>\n","protected":false},"author":1,"featured_media":2765,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[462],"class_list":["post-2754","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technology-modalities","tag-prime-editing"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2754","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2754"}],"version-history":[{"count":1,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2754\/revisions"}],"predecessor-version":[{"id":2774,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/posts\/2754\/revisions\/2774"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=\/wp\/v2\/media\/2765"}],"wp:attachment":[{"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2754"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2754"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.insilens.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2754"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}