{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T12:48:18Z","timestamp":1789130898727,"version":"build-2803163510"},"reference-count":50,"publisher":"Public Library of Science (PLoS)","issue":"8","license":[{"start":{"date-parts":[[2021,8,17]],"date-time":"2021-08-17T00:00:00Z","timestamp":1629158400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100007225","name":"Ministry of Science and Technology","doi-asserted-by":"publisher","award":["108.01-2019.306"],"award-info":[{"award-number":["108.01-2019.306"]}],"id":[{"id":"10.13039\/100007225","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Highly methylated Long Interspersed Nucleotide Elements 1 (<jats:italic>LINE-1<\/jats:italic>) constitute approximately 20% of the human genome, thus serving as a surrogate marker of global genomic DNA methylation. To date, there is still lacking a consensus about the precise location in <jats:italic>LINE-1<\/jats:italic> promoter and its methylation threshold value, making challenging the use of <jats:italic>LINE-1<\/jats:italic> methylation as a diagnostic, prognostic markers in cancer. This study reports on a technical standardization of bisulfite-based DNA methylation analysis, which ensures the complete bisulfite conversion of repeated <jats:italic>LINE-1<\/jats:italic> sequences, thus allowing accurate <jats:italic>LINE-1<\/jats:italic> methylation value. In addition, the study also indicated the precise location in <jats:italic>LINE-1<\/jats:italic> promoter of which significant variance in methylation level makes <jats:italic>LINE-1<\/jats:italic> methylation as a potential diagnostic biomarker for lung cancer. A serial concentration of 5-50-500 ng of DNA from 275 formalin-fixed paraffin-embedded lung tissues were converted by bisulfite; methylation level of two local regions (at nucleotide position 300\u2013368 as <jats:italic>LINE-1<\/jats:italic>.<jats:italic>1<\/jats:italic> and 368\u2013460 as <jats:italic>LINE-1<\/jats:italic>.<jats:italic>2<\/jats:italic>) in <jats:italic>LINE-1<\/jats:italic> promoter was measured by real time PCR. The use of 5 ng of genomic DNA but no more allowed to detect <jats:italic>LINE-1<\/jats:italic> hypomethylation in lung cancer tissue (14.34% versus 16.69% in non-cancerous lung diseases for <jats:italic>LINE-1<\/jats:italic>.<jats:italic>1<\/jats:italic>, p &lt; 0.0001, and 30.28% versus 32.35% for <jats:italic>LINE-1<\/jats:italic>.<jats:italic>2<\/jats:italic>, p &lt; 0.05). Our study thus highlighted the optimal and primordial concentration less than 5 ng of genomic DNA guarantees the complete <jats:italic>LINE-1<\/jats:italic> bisulfite conversion, and significant variance in methylation level of the <jats:italic>LINE-1<\/jats:italic> sequence position from 300 to 368 allowed to discriminate lung cancer from non-cancer samples.<\/jats:p>","DOI":"10.1371\/journal.pone.0256254","type":"journal-article","created":{"date-parts":[[2021,8,17]],"date-time":"2021-08-17T17:31:21Z","timestamp":1629221481000},"page":"e0256254","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":8,"title":["Standardization of DNA amount for bisulfite conversion for analyzing the methylation status of LINE-1 in lung cancer"],"prefix":"10.1371","volume":"16","author":[{"given":"Duong Anh Thuy","family":"Pham","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Son 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