333: Holistic determination of cfDNA ends

Jiang P et al., Cell Genomics - This episode reviews a Cell Genomics study that uses ssDNA '2-end' and novel '4-end' sequencing to profile native 5′ and 3′ termini of plasma cfDNA. The work identifies PREM/POEM markers, links 3′ ends to methylation, and shows improved HCC detection. Key terms: cfDNA fragmentomics, 3' end motifs, 4-end sequencing, hepatocellular carcinoma, DNASE1L3. Study Highlights:The authors adapted single-stranded library preparation (2-end sequencing) to measure native 5′ (EM5) and 3′ (EM3) end motifs and defined flanking PREM and POEM motifs. Combining size‑stratified PREM, EM5, EM3, and POEM features raised hepatocellular carcinoma (HCC) detection to an AUC of 0.95. Fragmentomics-based methylation analysis of 3′ ends (3′ FRAGMA) improved HCC detection further (AUC 0.97). A novel 4-end sequencing approach captured all four termini of double‑stranded cfDNA, yielding 4‑end motif models with AUC up to 0.98 and revealing coordinated nuclease activity, notably DNASE1L3 involvement. Conclusion:Holistic end profiling of cfDNA—integrating native 5′ and 3′ ends, flanking motifs, methylation-informed fragmentomics, and four‑end resolution—enhances cancer detection performance and provides mechanistic insight into coordinated nuclease-mediated fragmentation, warranting larger validation studies. Music:Enjoy the music based on this article at the end of the episode. Article title:Holistic determination of ends of cfDNA molecules First author:Jiang P Journal:Cell Genomics DOI:10.1016/j.xgen.2026.101142 Reference:Jiang P., Ma M.-J. L., Qiao R., et al. Holistic determination of ends of cfDNA molecules. Cell Genomics. 2026;6:101142. doi:10.1016/j.xgen.2026.101142 License:This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/ Support:Base by Base – Stripe donations: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00 Official website https://basebybase.com On PaperCast Base by Base you’ll discover the latest in genomics, functional genomics, structural genomics, and proteomics. Episode link: https://basebybase.com/episodes/holistic-cfdna-ends-episode-333 QC:This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-04-04. QC Scope:- article metadata and core scientific claims from the narration- excludes analogies, intro/outro, and music- transcript coverage: Audited the transcript’s substantive description of 2-end sequencing (EM5/EM3), PREM/POEM, 3'-FRAGMA, 4-end sequencing, nuclease signatures (DNASE1L3, DNASE1, DFFB), HCC diagnostic performance (AUC values), fragment-size context, and translational limitations as reported in the article.- transcript topics: 2-end sequencing preserving native ends (EM5/EM3); Pre-end (PREM) and post-end motifs (POEM); 4-end sequencing with stem-loop adapters and PacBio SMRT; 3'-FRAGMA methylation analysis; Nuclease-specific end motifs and coordinated fragmentation (DNASE1L3, DNASE1, DFFB); HCC detection performance and AUC values QC Summary:- factual score: 10/10- metadata score: 10/10- supported core claims: 8- claims flagged for review: 0- metadata checks passed: 4- metadata issues found: 0 Metadata Audited:- article_doi- article_title- article_journal- license Factual Items Audited:- 2-end sequencing preserves native 5' and 3' ends (EM5/EM3) by omitting end-repair during library prep- PREM and POEM motifs are defined and analyzed as end-motif neighbors around EM5 and EM3- 4-end sequencing enables simultaneous assessment of all four termini using stem-loop adapters and PacBio SMRT sequencing<...