{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,25]],"date-time":"2026-05-25T08:03:46Z","timestamp":1779696226133,"version":"3.53.1"},"reference-count":24,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,5,25]],"date-time":"2026-05-25T00:00:00Z","timestamp":1779667200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Servicio de Medicina Gen\u00f3mica, Instituto Nacional de Rehabilitaci\u00f3n Luis Guillermo Ibarra Ibarra (INRLGII), Mexico City, Mexico"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["CIMB"],"abstract":"<jats:p>Osteosarcoma is the most common primary bone tumor in children, adolescents, and young adults, and metastasis remains the main determinant for a poor outcome. We conducted an exploratory retrospective cohort study using formalin-fixed, paraffin-embedded tissue from 97 patients with histopathologically confirmed osteosarcoma treated between 2005 and 2019 to evaluate telomere maintenance mechanisms. To assess alternative lengthening of telomeres (ALT), colocalization of telomeric DNA and promyelocytic leukemia protein (TEL\u2013PML) was evaluated as a tissue-based proxy. TEL\u2013PML colocalization was assessed using combined PML immunofluorescence and telomere DNA PNA-FISH. Furthermore, telomerase reverse transcriptase (TERT) expression was evaluated by immunohistochemistry in relation to metastasis and disease progression. Logistic regression models were adjusted for age, sex, and smoking. TEL\u2013PML was evaluable in 45\/97 cases, including 10 positive and 35 negative tumors; the remaining samples were non-evaluable because of non-determinable signal or predominant necrosis. TERT immunohistochemistry was scorable in 58\/97 cases, of which 33 were positive. TEL\u2013PML evaluability was associated with amputation specimens, whereas TERT positivity was associated with non-osteoblastic histology and was inversely associated with age. Neither TEL\u2013PML nor TERT was significantly associated with metastasis, recurrence, or death. Exploratory time-to-metastasis curves suggested an earlier increase of metastatic events among TEL\u2013PML-positive cases. However, the small number of positive tumors precludes definitive prognostic interpretation. These hypothesis-generating findings indicate that TEL\u2013PML assessment is feasible in osteosarcoma, but it is strongly influenced by tissue adequacy. On the other hand, TERT immunohistochemistry appears to reflect subtype- and age-related heterogeneity rather than providing robust outcome stratification in this cohort.<\/jats:p>","DOI":"10.3390\/cimb48060553","type":"journal-article","created":{"date-parts":[[2026,5,25]],"date-time":"2026-05-25T06:42:18Z","timestamp":1779691338000},"page":"553","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Telomeric DNA\u2013Promyelocytic Leukemia (TEL\u2013PML) Colocalization as an ALT Proxy in Relation to Metastatic Behavior in Osteosarcoma: A Retrospective Cohort Study"],"prefix":"10.3390","volume":"48","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3976-4759","authenticated-orcid":false,"given":"Rogelio Frank","family":"Jim\u00e9nez-Ortega","sequence":"first","affiliation":[{"name":"Servicio de Medicina Gen\u00f3mica, Instituto Nacional de Rehabilitaci\u00f3n Luis Guillermo Ibarra Ibarra (INRLGII), Mexico City 14389, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rosa M.","family":"Salgado","sequence":"additional","affiliation":[{"name":"Laboratorio de Tejido Conjuntivo, Instituto Nacional de Rehabilitaci\u00f3n Luis Guillermo Ibarra Ibarra (INRLGII), Mexico City 14389, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9845-024X","authenticated-orcid":false,"given":"Berenice","family":"Rivera-Paredez","sequence":"additional","affiliation":[{"name":"Centro de Investigaci\u00f3n en Pol\u00edticas, Poblaci\u00f3n y Salud, Facultad de Medicina, Universidad Nacional Aut\u00f3noma de M\u00e9xico, Mexico City 04510, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nelly","family":"Pati\u00f1o","sequence":"additional","affiliation":[{"name":"Unidad de Citometr\u00eda de Flujo (UCiF), Instituto Nacional de Medicina Gen\u00f3mica (INMEGEN), Mexico City 14610, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tania","family":"Hilario-Huerta","sequence":"additional","affiliation":[{"name":"Servicio de Medicina Gen\u00f3mica, Instituto Nacional de Rehabilitaci\u00f3n Luis Guillermo Ibarra Ibarra (INRLGII), Mexico City 14389, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Silvia","family":"Arenas-D\u00edaz","sequence":"additional","affiliation":[{"name":"Servicio de Medicina Gen\u00f3mica, Instituto Nacional de Rehabilitaci\u00f3n Luis Guillermo Ibarra Ibarra (INRLGII), Mexico City 14389, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4515-0777","authenticated-orcid":false,"given":"Rafael","family":"Vel\u00e1zquez-Cruz","sequence":"additional","affiliation":[{"name":"Laboratorio de Gen\u00f3mica del Metabolismo \u00d3seo, Instituto Nacional de Medicina Gen\u00f3mica (INMEGEN), Mexico City 14610, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2506-8784","authenticated-orcid":false,"given":"Alberto","family":"Hidalgo-Bravo","sequence":"additional","affiliation":[{"name":"Servicio de Medicina Gen\u00f3mica, Instituto Nacional de Rehabilitaci\u00f3n Luis Guillermo Ibarra Ibarra (INRLGII), Mexico City 14389, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"722","DOI":"10.1038\/nrc3838","article-title":"Translational biology of osteosarcoma","volume":"14","author":"Kansara","year":"2014","journal-title":"Nat. Rev. Cancer"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3029","DOI":"10.1200\/JCO.2014.59.4895","article-title":"Osteosarcoma: Current treatment and a collaborative pathway to success","volume":"33","author":"Isakoff","year":"2015","journal-title":"J. Clin. Oncol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1186\/s13578-020-00391-6","article-title":"Alternative lengthening of telomeres: From molecular mechanisms to therapeutic outlooks","volume":"10","author":"Zhang","year":"2020","journal-title":"Cell Biosci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1608","DOI":"10.1016\/j.ajpath.2011.06.018","article-title":"Prevalence of the alternative lengthening of telomeres telomere maintenance mechanism in human cancer subtypes","volume":"179","author":"Heaphy","year":"2011","journal-title":"Am. J. Pathol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1158\/1078-0432.217.11.1","article-title":"A robust assay for alternative lengthening of telomeres in tumors shows the significance of alternative lengthening of telomeres in sarcomas and astrocytomas","volume":"11","author":"Henson","year":"2005","journal-title":"Clin. Cancer Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1002\/gcc.20074","article-title":"Divergent patterns of telomere maintenance mechanisms among human sarcomas: Sharply contrasting prevalence of the alternative lengthening of telomeres mechanism in Ewing\u2019s sarcomas and osteosarcomas","volume":"41","author":"Ulaner","year":"2004","journal-title":"Genes Chromosomes Cancer"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Burrow, T.A., Koneru, B., Macha, S.J., Sun, W., Barr, F.G., Triche, T.J., and Reynolds, C.P. (2024). Prevalence of alternative lengthening of telomeres in pediatric sarcomas determined by the telomeric DNA C-circle assay. Front. Oncol., 14.","DOI":"10.3389\/fonc.2024.1399442"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"MacKenzie, D., Watters, A.K., To, J.T., Young, M.W., Muratori, J., Wilkoff, M.H., Abraham, R.G., Plummer, M.M., and Zhang, D. (2021). ALT positivity in human cancers: Prevalence and clinical insights. Cancers, 13.","DOI":"10.3390\/cancers13102384"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1545","DOI":"10.1038\/modpathol.2015.114","article-title":"Comprehensive screening of alternative lengthening of telomeres phenotype and loss of ATRX expression in sarcomas","volume":"28","author":"Liau","year":"2015","journal-title":"Mod. Pathol."},{"key":"ref_10","first-page":"1759","article-title":"Absence of a telomere maintenance mechanism as a favorable prognostic factor in patients with osteosarcoma","volume":"63","author":"Ulaner","year":"2003","journal-title":"Cancer Res."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Lawlor, R.T., Veronese, N., Pea, A., Nottegar, A., Smith, L., Pilati, C., Demurtas, J., Fassan, M., Cheng, L., and Luchini, C. (2019). Alternative lengthening of telomeres (ALT) influences survival in soft tissue sarcomas: A systematic review with meta-analysis. BMC Cancer, 19.","DOI":"10.1186\/s12885-019-5424-8"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Odri, G.A., Tchicaya-Bouanga, J., Yoon, D.J.Y., and Modrowski, D. (2022). Metastatic progression of osteosarcomas: A review of current knowledge of environmental versus oncogenic drivers. Cancers, 14.","DOI":"10.3390\/cancers14020360"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"971","DOI":"10.4103\/ijo.IJO_1342_21","article-title":"Immunohistochemical and mutational status of telomerase reverse transcriptase in conjunctival squamous cell carcinoma","volume":"70","author":"Jayaraj","year":"2022","journal-title":"Indian J. Ophthalmol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1520","DOI":"10.5858\/arpa.2013-0691-RA","article-title":"A review of preanalytical factors affecting molecular, protein, and morphological analysis of formalin-fixed, paraffin-embedded tissue: How well do you know your FFPE specimen?","volume":"138","author":"Bass","year":"2014","journal-title":"Arch. Pathol. Lab. Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.jclinepi.2021.01.008","article-title":"Framework for the treatment and reporting of missing data in observational studies: The Treatment and Reporting of Missing Data in Observational Studies framework","volume":"134","author":"Lee","year":"2021","journal-title":"J. Clin. Epidemiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"b2393","DOI":"10.1136\/bmj.b2393","article-title":"Multiple imputation for missing data in epidemiological and clinical research: Potential and pitfalls","volume":"338","author":"Sterne","year":"2009","journal-title":"BMJ"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2065","DOI":"10.7150\/ijms.97485","article-title":"Telomeres and telomerase in sarcoma disease and therapy","volume":"21","author":"Huang","year":"2024","journal-title":"Int. J. Med. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3835","DOI":"10.1038\/sj.onc.1204493","article-title":"Alternative lengthening of telomeres is associated with chromosomal instability in osteosarcomas","volume":"20","author":"Scheel","year":"2001","journal-title":"Oncogene"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1253","DOI":"10.1021\/acsptsci.0c00125","article-title":"Selective elimination of osteosarcoma cell lines with short telomeres by ataxia telangiectasia and Rad3-related inhibitors","volume":"3","author":"Goncalves","year":"2020","journal-title":"ACS Pharmacol. Transl. Sci."},{"key":"ref_20","first-page":"e15859","article-title":"TOP3A amplification and ATRX inactivation are mutually exclusive events in pediatric osteosarcomas using ALT","volume":"14","author":"Salas","year":"2022","journal-title":"EMBO Mol. Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3790","DOI":"10.1200\/JCO.2004.03.043","article-title":"Telomerase expression predicts unfavorable outcome in osteosarcoma","volume":"22","author":"Sanders","year":"2004","journal-title":"J. Clin. Oncol."},{"key":"ref_22","first-page":"1307","article-title":"Analysis of telomerase activity and telomere length in bone and soft tissue tumors","volume":"11","author":"Terasaki","year":"2004","journal-title":"Oncol. Rep."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1038","DOI":"10.1002\/mc.22824","article-title":"hTERT promotes tumor progression by enhancing TSPAN13 expression in osteosarcoma cells","volume":"57","author":"Jaiswal","year":"2018","journal-title":"Mol. Carcinog."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1203\/01.PDR.0000102455.36737.3C","article-title":"Telomerase activity and telomere length in primary and metastatic tumors from pediatric bone cancer patients","volume":"55","year":"2004","journal-title":"Pediatr. Res."}],"container-title":["Current Issues in Molecular Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1467-3045\/48\/6\/553\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,25]],"date-time":"2026-05-25T07:29:13Z","timestamp":1779694153000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1467-3045\/48\/6\/553"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,25]]},"references-count":24,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,6]]}},"alternative-id":["cimb48060553"],"URL":"https:\/\/doi.org\/10.3390\/cimb48060553","relation":{},"ISSN":["1467-3045"],"issn-type":[{"value":"1467-3045","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,25]]}}}