{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T18:44:48Z","timestamp":1783536288620,"version":"3.55.0"},"reference-count":35,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T00:00:00Z","timestamp":1783468800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Education and Science of Russia for the Research Centre for Medical Genetics"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Genetically modified hematopoietic stem cell therapy using gene-modified autologous hematopoietic stem cells has evolved over the last 30 years as an alternative approach to circumvent the limitations of donor availability, risks of excessive regimen related toxicity, prolonged immune suppression and graft-versus-host disease associated with allogeneic hematopoietic cell transplantation. Gene replacement therapy based on viral insertion of transgene into host genome was developed as one of the main methods for gene modification of autologous cells. Unfortunately, many cases of oncogenesis were directly caused by genetically modified hematopoietic stem cell therapy. The purpose of the present review is the description of cases of leukemogenesis in gene replacement therapy in hematopoietic stem cells, elucidation of the causes, and overview of the risk mitigation strategies. It aims to elucidate the main risk factors in gene replacement therapy in hematopoietic stem cells. The insertional mutagenesis leads to activation of proto-oncogenes, mostly LMO2 and MECOM-EVI1. \u03b3-retroviral vectors are dangerous in this case, as they contain long terminal repeats with strong promotor activity and are prone to integration near transcription initiation sites. Therefore, safer self-inactivating lentiviral vectors were developed, with long terminal repeats modified to reduce their promoter activity and with safer integration pattern. Nevertheless, the risk of leukemogenesis remains because the promoter integrated into the transgene expression cassette may still influence nearby gene expression. Another risk factor is monosomy 7, either pre-existing or caused by MECOM-EVI1 activation, which may contribute directly to leukemogenesis. Thus, oncogenesis in HSPC gene replacement therapy does not have a single definitive cause; rather, multiple factors may contribute, and each may be sufficient under specific conditions.<\/jats:p>","DOI":"10.3390\/ijms27146098","type":"journal-article","created":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T17:27:31Z","timestamp":1783531651000},"page":"6098","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Oncogenesis as an Adverse Effect of Gene Replacement Therapy in Hematopoietic Stem Cells"],"prefix":"10.3390","volume":"27","author":[{"given":"Irina O.","family":"Petrova","sequence":"first","affiliation":[{"name":"Laboratory of Genome Editing, Research Centre for Medical Genetics, Moskvorechye 1, 115478 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1558-3048","authenticated-orcid":false,"given":"Svetlana A.","family":"Smirnikhina","sequence":"additional","affiliation":[{"name":"Laboratory of Genome Editing, Research Centre for Medical Genetics, Moskvorechye 1, 115478 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3376","DOI":"10.1016\/j.ymthe.2023.11.001","article-title":"The state of cell and gene therapy in 2023","volume":"31","author":"Chancellor","year":"2023","journal-title":"Mol. Ther."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e177","DOI":"10.1016\/j.bbmt.2020.04.013","article-title":"Current Use of and Trends in Hematopoietic Cell Transplantation in the United States","volume":"26","author":"Fretham","year":"2020","journal-title":"Biol. Blood Marrow Transplant."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Petrova, I.O., and Smirnikhina, S.A. (2025). Ex Vivo Gene and Cell Therapy in Hematopoietic Stem Cells. Int. J. Mol. Sci., 26.","DOI":"10.3390\/ijms262311466"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3662","DOI":"10.1038\/s41467-024-47866-5","article-title":"A case of T-cell acute lymphoblastic leukemia in retroviral gene therapy for ADA-SCID","volume":"15","author":"Cesana","year":"2024","journal-title":"Nat. Commun."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1287","DOI":"10.1056\/NEJMoa2405541","article-title":"Hematologic Cancer after Gene Therapy for Cerebral Adrenoleukodystrophy","volume":"391","author":"Duncan","year":"2024","journal-title":"N. Engl. J. Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1056\/NEJMoa2109167","article-title":"Acute Myeloid Leukemia Case after Gene Therapy for Sickle Cell Disease","volume":"386","author":"Goyal","year":"2022","journal-title":"N. Engl. J. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1002\/ajh.26741","article-title":"Lovo-cel gene therapy for sickle cell disease: Treatment process evolution and outcomes in the initial groups of the HGB -206 study","volume":"98","author":"Kanter","year":"2023","journal-title":"Am. J. Hematol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3132","DOI":"10.1172\/JCI35700","article-title":"Insertional oncogenesis in 4 patients after retrovirus-mediated gene therapy of SCID-X1","volume":"118","author":"Garrigue","year":"2008","journal-title":"J. Clin. Investig."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1056\/NEJMoa1000164","article-title":"Efficacy of Gene Therapy for X-Linked Severe Combined Immunodeficiency","volume":"363","author":"Hauer","year":"2010","journal-title":"N. Engl. J. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1038\/nm1393","article-title":"Correction of X-linked chronic granulomatous disease by gene therapy, augmented by insertional activation of MDS1-EVI1, PRDM16 or SETBP1","volume":"12","author":"Ott","year":"2006","journal-title":"Nat. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3424","DOI":"10.1016\/j.ymthe.2023.09.004","article-title":"Myelodysplasia after clonal hematopoiesis with APOBEC3-mediated CYBB inactivation in retroviral gene therapy for X-CGD","volume":"31","author":"Uchiyama","year":"2023","journal-title":"Mol. Ther."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"227ra33","DOI":"10.1126\/scitranslmed.3007280","article-title":"Gene Therapy for Wiskott-Aldrich Syndrome\u2014Long-Term Efficacy and Genotoxicity","volume":"6","author":"Braun","year":"2014","journal-title":"Sci. Transl. Med."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1002\/rmv.592","article-title":"Oncogenesis by retroviruses: Old and new paradigms","volume":"18","author":"Maeda","year":"2008","journal-title":"Rev. Med. Virol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1016\/j.ymthe.2019.12.009","article-title":"Retroviral Insertional Mutagenesis in Humans: Evidence for Four Genetic Mechanisms Promoting Expansion of Cell Clones","volume":"28","author":"Bushman","year":"2020","journal-title":"Mol. Ther."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"669","DOI":"10.1126\/science.288.5466.669","article-title":"Gene Therapy of Human Severe Combined Immunodeficiency (SCID)-X1 Disease","volume":"288","author":"Basile","year":"2000","journal-title":"Science"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1038\/sj.leu.2404008","article-title":"Cyclin D2 dysregulation by chromosomal translocations to TCR loci in T-cell acute lymphoblastic leukemias","volume":"20","author":"Clappier","year":"2006","journal-title":"Leukemia"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1770","DOI":"10.1182\/blood-2007-01-068759","article-title":"Hot spots of retroviral integration in human CD34+ hematopoietic cells","volume":"110","author":"Cattoglio","year":"2007","journal-title":"Blood"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"4079","DOI":"10.1038\/s41388-022-02414-7","article-title":"A comprehensive analysis of LMO2 pathogenic regulatory profile during T-lineage development and leukemic transformation","volume":"41","author":"Wang","year":"2022","journal-title":"Oncogene"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"7541","DOI":"10.1128\/jvi.69.12.7541-7547.1995","article-title":"Novel retroviral vectors for efficient expression of the multidrug resistance (mdr-1) gene in early hematopoietic cells","volume":"69","author":"Baum","year":"1995","journal-title":"J. Virol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1038\/nm.2088","article-title":"Genomic instability and myelodysplasia with monosomy 7 consequent to EVI1 activation after gene therapy for chronic granulomatous disease","volume":"16","author":"Stein","year":"2010","journal-title":"Nat. Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"4791","DOI":"10.1200\/JCO.2008.16.0259","article-title":"Monosomal Karyotype in Acute Myeloid Leukemia: A Better Indicator of Poor Prognosis Than a Complex Karyotype","volume":"26","author":"Breems","year":"2008","journal-title":"J. Clin. Oncol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2891","DOI":"10.1182\/blood-2017-12-822262","article-title":"The enigma of monosomy 7","volume":"131","author":"Inaba","year":"2018","journal-title":"Blood"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1699","DOI":"10.1084\/jem.191.10.1699","article-title":"Comparative Analysis of Genetically Modified Dendritic Cells and Tumor Cells as Therapeutic Cancer Vaccines","volume":"191","author":"Klein","year":"2000","journal-title":"J. Exp. Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1749","DOI":"10.1126\/science.1083413","article-title":"Transcription Start Regions in the Human Genome Are Favored Targets for MLV Integration","volume":"300","author":"Wu","year":"2003","journal-title":"Science"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"848","DOI":"10.1038\/nrmicro1263","article-title":"Genome-wide analysis of retroviral DNA integration","volume":"3","author":"Bushman","year":"2005","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Hematti, P., Hong, B.-K., Ferguson, C., Adler, R., Hanawa, H., Sellers, S., Holt, I.E., Eckfeldt, C.E., Sharma, Y., and Schmidt, M. (2004). Distinct Genomic Integration of MLV and SIV Vectors in Primate Hematopoietic Stem and Progenitor Cells. PLoS Biol., 2.","DOI":"10.1371\/journal.pbio.0020423"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1173","DOI":"10.1111\/bjh.20020","article-title":"Longitudinal analysis of lentiviral and retroviral chimeric antigen receptors\u2019 integration sites reveals distinct clonal evolutionary patterns","volume":"206","author":"Guiraud","year":"2025","journal-title":"Br. J. Haematol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"964","DOI":"10.1172\/JCI37630","article-title":"The genotoxic potential of retroviral vectors is strongly modulated by vector design and integration site selection in a mouse model of HSC gene therapy","volume":"119","author":"Montini","year":"2009","journal-title":"J. Clin. Investig."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"4395","DOI":"10.1182\/blood-2011-03-340711","article-title":"Ubiquitous high-level gene expression in hematopoietic lineages provides effective lentiviral gene therapy of murine Wiskott-Aldrich syndrome","volume":"119","author":"Astrakhan","year":"2012","journal-title":"Blood"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1159","DOI":"10.1177\/10430342251372474","article-title":"Risk and Benefit Assessment of Gene Therapy with Lentiviral Vectors and Hematopoietic Stem Cells: The Skysona Case","volume":"36","author":"Rio","year":"2025","journal-title":"Hum. Gene Ther."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Fr\u00f6bel, J., Landspersky, T., Percin, G., Schreck, C., Rahmig, S., Ori, A., Nowak, D., Essers, M., Waskow, C., and Oostendorp, R.A.J. (2021). The Hematopoietic Bone Marrow Niche Ecosystem. Front. Cell Dev. Biol., 9.","DOI":"10.3389\/fcell.2021.705410"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2060","DOI":"10.1002\/eji.200838383","article-title":"Space-time considerations for hematopoietic stem cell transplantation","volume":"38","author":"Bhattacharya","year":"2008","journal-title":"Eur. J. Immunol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1628","DOI":"10.1016\/j.bbmt.2009.07.004","article-title":"Defining the Intensity of Conditioning Regimens: Working Definitions","volume":"15","author":"Bacigalupo","year":"2009","journal-title":"Biol. Blood Marrow Transplant."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Okalova, J., Spencer, T.H., and Chandrakasan, S. (2025). Next generation targeted non-genotoxic conditioning for hematopoietic stem cell and hematopoietic stem cell-based gene therapy. Front. Immunol., 16.","DOI":"10.3389\/fimmu.2025.1653344"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/j.ymthe.2020.11.020","article-title":"Update on Clinical Ex Vivo Hematopoietic Stem Cell Gene Therapy for Inherited Monogenic Diseases","volume":"29","author":"Tucci","year":"2021","journal-title":"Mol. Ther."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/14\/6098\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T17:30:20Z","timestamp":1783531820000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/14\/6098"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,8]]},"references-count":35,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["ijms27146098"],"URL":"https:\/\/doi.org\/10.3390\/ijms27146098","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,8]]}}}