Аннотация
Целью работы является обзор научной литературы о генетических мутациях, возникающих при хроническом лимфоцитарном лейкозе. Материал и методы. Для поиска опубликованных исследований использовались следующие базы данных: PubMed, Web of Science, EBSCOhost и Scopus. Поиск производился во временном интервале с даты создания соответствующей базы данных до октября 2024 г. Исследование признавалось подходящим, в случае если оно было оригинальным, рассматривало клинические и патогенетические особенности ХЛЛ. Результаты. Из представленного анализа литературных источников следует, что основными генетическими изменениями при ХЛЛ являются хромосомные мутации. При этом наиболее распространенной аномалией является делеция del(13q14) и del(17p). Также при ХЛЛ большое значение имеет микроокружение. Поведение клеток ХЛЛ зависит от сигналов, источником которых являются находящиеся в микроокружении неопухолевые клетки. Геном опухолей многих пациентов с ХЛЛ характеризуется наличием мутаций в генах вариабельного региона тяжелой цепи иммуноглобулинов, в то время как у других пациентов вышеупомянутые гены не содержат мутаций, что ассоциировано с неблагоприятным прогнозом заболевания. Заключение. В обзоре проанализированы различные виды аномалий при ХЛЛ. Рассмотрены основные этапы патогенетического механизма в эволюции заболевания и возможные способы лечения в зависимости от генетической мутации.
Авторы и аффилиации
А.Г. Гарифуллина(1), И.Р. Гилязова(1–3), Г.Р. Абдеева(1), Д.А. Кудлай(4–6),
А.Р. Низамова(2), А.А. Минязова(1), Б.А. Бакиров(1)
1-ФГБОУ ВО «Башкирский государственный медицинский университет»
Министерства здравоохранения Российской Федерации,
Российская Федерация, Республика Башкортостан, 450008, Уфа, ул. Ленина, д. 3;
2-Институт биохимии и генетики Уфимского Федерального
исследовательского центра РАН, Российская Федерация,
Республика Башкортостан, 450054, Уфа, проспект Октября, д. 71;
3-ФГБОУ ВО «Санкт-Петербургский государственный университет»,
Российская Федерация, 199034, Санкт-Петербург, Университетская наб., 7–9;
4-ФГАОУ ВО «Первый Московский государственный медицинский университет
им. И.М. Сеченова» Министерства здравоохранения Российской Федерации,
Российская Федерация, 119991, Москва, ул. Трубецкая, д. 8, стр. 2;
5-Московский государственный университет им. М.В. Ломоносова,
Российская Федерация, 119991, Москва, ул. Ленинские горы, д. 1;
6-ФГБУ «Государственный Научный центр Института иммунологии»
Федеральное медико-биологическое агентство России,
Российская Федерация, 115522, Москва, ул. Каширское ш., д. 24
Литература
Chronic Lymphocytic Leukemia. Cancer Stat Facts. [Электронное издание]. Режим доступа: https://seer.cancer.gov/statfacts/html/clyl.html. Chronic Lymphocytic Leukemia. Cancer Stat Facts. [Electronic resource]. Access mode: https://seer.cancer.gov/statfacts/html/clyl.html.
Sant M., Allemani C., Tereanu C., De Angelis R., Capocaccia R., Visser O., Marcos-Gragera R. et al. Incidence of hematologic malignancies in Europe by morphologic subtype: results of the HAEMACARE project. Blood. 2010; 116 (19): 3724–34. https://doi.org/10.1182/blood-2010-05-282632
Hamblin T.J., Davis Z., Gardiner A., Oscier D.G., Stevenson F.K. Unmutated Ig VH Genes Are Associated With a More Aggressive Form of Chronic Lymphocytic Leukemia. Blood. 1999; 94 (6): 1848–54. https://doi.org/10.1182/blood.V94.6.1848
Klein U., Lia M., Crespo M., Siegel R., Shen Q., Mo T., Ambesi-Impiombato A. et al. The DLEU2/miR-15a/16-1 cluster controls B cell proliferation and its deletion leads to chronic lymphocytic leukemia. Cancer Cell. 2010; 17 (1): 28–40. https://doi.org/10.1016/j.ccr.2009.11.019
Thompson P.A., Srivastava J., Peterson C., Strati P., Jorgensen J.L., Hether T., Keating M.J. et al. Minimal residual disease undetectable by next-generation sequencing predicts improved outcome in CLL after chemoimmunotherapy. Blood. 2019; 134 (22): 1951–9. https://doi.org/10.1182/blood.2019001077
Hallek M., Cheson B.D., Catovsky D., Caligaris-Cappio F., Dighiero G., Döhner H., Hillmen P. et al. iwCLL guidelines for diagnosis, indications for treatment, response assessment, and supportive management of CLL. Blood. 2018; 131 (25): 2745–60. https://doi.org/10.1182/blood-2017-09-806398
Kikushige Y., Ishikawa F., Miyamoto T., Shima T., Urata S., Yoshimoto G., Mori Y. et al. Self-renewing hematopoietic stem cell is the primary target in pathogenesis of human chronic lymphocytic leukemia. Cancer Cell. 2011; 20 (2): 246–59. https://doi.org/10.1016/j.ccr.2011.06.029
Döhner H., Stilgenbauer S., Benner A., Leupolt E., Kröber A., Bullinger L., Döhner K., Bentz M., Lichter P. Genomic aberrations and survival in chronic lymphocytic leukemia. N Engl J. Med. 2000; 343 (26): 1910–6. https://doi.org/10.1056/NEJM200012283432602
Hallek M., Fischer K., Fingerle-Rowson G., Fink A.M., Busch R., Mayer J., Hensel M. et al. Addition of rituximab to fludarabine and cyclophosphamide in patients with chronic lymphocytic leukaemia: a randomised, open-label, phase 3 trial. Lancet Lond Engl. 2010; 376 (9747): 1164–74. https://doi.org/10.1016/S0140-6736(10)61381-5
Zenz T., Vollmer D., Trbusek M., Smardova J., Benner A., Soussi T., Helfrich H. et al. TP53 mutation profile in chronic lymphocytic leukemia: evidence for a disease specific profile from a comprehensive analysis of 268 mutations. Leukemia. 2010; 24 (12): 2072–9. https://doi.org/10.1038/leu.2010.208
Seiffert M., Dietrich S., Jethwa A., Glimm H., Lichter P., Zenz T. Exploiting biological diversity and genomic aberrations in chronic lymphocytic leukemia. Leuk Lymphoma. 2012; 53 (6): 1023–31. https://doi.org/10.3109/10428194.2011.631638
Zenz T., Mertens D., Küppers R., Döhner H., Stilgenbauer S. From pathogenesis to treatment of chronic lymphocytic leukaemia. Nat Rev Cancer. 2010; 10 (1): 37–50. https://doi.org/10.1038/nrc2764
Quesada V., Conde L., Villamor N., Ordóñez G.R., Jares P., Bassaganyas L., Ramsay A.J. et al. Exome sequencing identifies recurrent mutations of the splicing factor SF3B1 gene in chronic lymphocytic leukemia. Nat Genet. 2011; 44 (1): 47–52. https://doi.org/10.1038/ng.1032
Döhner H., Stilgenbauer S., James M.R., Benner A., Weilguni T., Bentz M., Fischer K., Hunstein W., Lichter P. 11q deletions identify a new subset of B-cell chronic lymphocytic leukemia characterized by extensive nodal involvement and inferior prognosis. Blood. 1997; 89 (7): 2516–22.
Landau D.A., Tausch E., Taylor-Weiner A.N., Stewart C., Reiter J.G., Bahlo J., Kluth S. et al. Mutations driving CLL and their evolution in progression and relapse. Nature. 2015; 526 (7574): 525–30. https://doi.org/10.1038/nature15395
Puente X.S., Pinyol M., Quesada V., Conde L., Ordóñez G.R., Villamor N., Escaramis G. et al. Whole-genome sequencing identifies recurrent mutations in chronic lymphocytic leukaemia. Nature. 2011; 475 (7354): 101–5. https://doi.org/10.1038/nature10113
Puente X.S., Beà S., Valdés-Mas R., Villamor N., Gutiérrez-Abril J., Martin-Subero J.I., Munar M., Rubio-Pérez C. et al. Non-coding recurrent mutations in chronic lymphocytic leukaemia. Nature. 2015; 526 (7574): 519–24. https://doi.org/10.1038/nature14666
Jackson S.P., Bartek J. The DNA-damage response in human biology and disease. Nature. 2009; 461 (7267): 1071–8. https://doi.org/10.1038/nature08467
Calin G.A., Dumitru C.D., Shimizu M., Bichi R., Zupo S., Noch E., Aldler H. et al. Frequent deletions and down-regulation of micro- RNA genes miR15 and miR16 at 13q14 in chronic lymphocytic leukemia. Proc Natl Acad Sci USA. 2002; 99 (24): 15524–9. https://doi.org/10.1073/pnas.242606799
Fabbri M., Bottoni A., Shimizu M., Spizzo R., Nicoloso M.S., Rossi S., Barbarotto E. et al. Association of a microRNA/TP53 feedback circuitry with pathogenesis and outcome of B-cell chronic lymphocytic leukemia. JAMA. 2011; 305 (1): 59–67. https://doi.org/10.1001/jama.2010.1919
Mraz M., Kipps T.J. MicroRNAs and B cell receptor signaling in chronic lymphocytic leukemia. Leuk Lymphoma. 2013; 54 (8): 1836–9. https://doi.org/10.3109/10428194.2013.796055
Balatti V., Rizzotto L., Miller C., Palamarchuk A., Fadda P., Pandolfo R., Rassenti L.Z., Hertlein E. et al. TCL1 targeting miR-3676 is codeleted with tumor protein p53 in chronic lymphocytic leukemia. Proc Natl Acad Sci USA. 2015; 112 (7): 2169–74. https://doi.org/10.1073/pnas.1500010112
Bichi R., Shinton S.A., Martin E.S., Koval A., Calin G.A., Cesari R., Russo G., Hardy R.R., Croce C.M. Human chronic lymphocytic leukemia modeled in mouse by targeted TCL1 expression. Proc Natl Acad Sci USA. 2002; 99 (10): 6955–60. https://doi.org/10.1073/pnas.102181599
Costinean S., Zanesi N., Pekarsky Y., Tili E., Volinia S., Heerema N., Croce C.M. Pre-B cell proliferation and lymphoblastic leukemia/high-grade lymphoma in E(mu)-miR155 transgenic mice. Proc Natl Acad Sci USA. 2006; 103 (18): 7024–9. https://doi.org/10.1073/pnas.0602266103
Cui B., Chen L., Zhang S., Mraz M., Fecteau J.F., Yu J., Ghia E.M. et al. MicroRNA-155 influences B-cell receptor signaling and associates with aggressive disease in chronic lymphocytic leukemia. Blood. 2014; 124 (4): 546–54. https://doi.org/10.1182/blood-2014-03-559690
Cahill N., Bergh A.C., Kanduri M., Göransson-Kultima H., Mansouri L., Isaksson A., Ryan F., Smedby K.E., Juliusson G., Sundström C., Rosén A., Rosenquist R. 450K-array analysis of chronic lymphocytic leukemia cells reveals global DNA methylation to be relatively stable over time and similar in resting and proliferative compartments. Leukemia. 2013; 27 (1): 150–8. https://doi.org/10.1038/leu.2012.245
Wahlfors J., Hiltunen H., Heinonen K., Hämäläinen E., Alhonen L., Jänne J. Genomic hypomethylation in human chronic lymphocytic leukemia. Blood. 1992; 80 (8): 2074–80.
Ziller M.J., Gu H., Müller F., Donaghey J., Tsai L.T., Kohlbacher O., De Jager P.L., Rosen E.D., Bennett D.A., Bernstein B.E., Gnirke A., Meissner A. Charting a dynamic DNA methylation landscape of the human genome. Nature. 2013; 500 (7463): 477–81. https://doi.org/10.1038/nature12433
Kulis M., Heath S., Bibikova M., Queirós A.C., Navarro A., Clot G., Martinez-Trillos A. et al. Epigenomic analysis detects widespread gene-body DNA hypomethylation in chronic lymphocytic leukemia. Nat Genet. 2012; 44 (11): 1236–42. https://doi.org/10.1038/ng.2443
Landau D.A., Clement K., Ziller M.J., Boyle P., Fan J., Gu H., Stevenson K. et al. Locally disordered methylation forms the basis of intratumor methylome variation in chronic lymphocytic leukemia. Cancer Cell. 2014; 26 (6): 813–25. https://doi.org/10.1016/j.ccell.2014.10.012
Oakes C.C., Claus R., Gu L., Assenov Y., Hüllein J., Zucknick M., Bieg M., Brocks D. et al. Evolution of DNA methylation is linked to genetic aberrations in chronic lymphocytic leukemia. Cancer Discov. 2014; 4 (3): 348–61. https://doi.org/10.1158/2159-8290.CD-13-0349
Pei L., Choi J.H., Liu J., Lee E.J., McCarthy B., Wilson J.M., Speir E. et al. Genome-wide DNA methylation analysis reveals novel epigenetic changes in chronic lymphocytic leukemia. Epigenetics. 2012; 7 (6): 567–78. https://doi.org/10.4161/epi.20237
Queirós A.C., Villamor N., Clot G., Martinez-Trillos A., Kulis M., Navarro A., Penas E.M. et al. A B-cell epigenetic signature defines three biologic subgroups of chronic lymphocytic leukemia with clinical impact. Leukemia. 2015; 29 (3): 598–605. https://doi.org/10.1038/leu.2014.252
Bhoi S., Ljungström V., Baliakas P., Mattsson M., Smedby K.E., Juliusson G., Rosenquist R. et al. Prognostic impact of epigenetic classification in chronic lymphocytic leukemia: The case of subset #2. Epigenetics. 2016; 11 (6): 449–55. https://doi.org/10.1080/15592294.2016.1178432
Oakes C.C., Seifert M., Assenov Y., Gu L., Przekopowitz M., Ruppert A.S., Wang Q. et al. DNA methylation dynamics during B cell maturation underlie a continuum of disease phenotypes in chronic lymphocytic leukemia. Nat Genet. 2016; 48 (3): 253–64. https://doi.org/10.1038/ng.3488
Herishanu Y., Pérez-Galán P., Liu D., Biancotto A., Pittaluga S., Vire, B., Gibellini F. et al. The lymph node microenvironment promotes B-cell receptor signaling, NF-kappaB activation, and tumor proliferation in chronic lymphocytic leukemia. Blood. 2011; 117 (2): 563–74. https://doi.org/10.1182/blood-2010-05-284984
Packham G., Krysov S., Allen A., Savelyeva N., Steele A.J., Forconi F., Stevenson F.K. The outcome of B-cell receptor signaling in chronic lymphocytic leukemia: proliferation or anergy. Haematologica. 2014; 99 (7): 1138–48. https://doi.org/10.3324/haematol.2013.098384
Endo T., Nishio M., Enzler T., Cottam H.B., Fukuda T., James D.F., Karin M., Kipps T. J. BAFF and APRIL support chronic lymphocytic leukemia B-cell survival through activation of the canonical NF-kappaB pathway. Blood. 2007; 109 (2): 703–10. https://doi.org/10.1182/blood-2006-06-027755
Cui B., Chen L., Zhang S., Mraz M., Fecteau J.F., Yu J., Ghia E.M. et al. MicroRNA-155 influences B-cell receptor signaling and associates with aggressive disease in chronic lymphocytic leukemia. Blood. 2014; 124 (4): 546–54. https://doi.org/10.1182/blood-2014-03-559690
Aguilar-Hernandez M.M., Blunt M.D., Dobson R., Yeomans A., Thirdborough S., Larrayoz M., Smith L.D. et al. IL-4 enhances expression and function of surface IgM in CLL cells. Blood. 2016; 127 (24): 3015–25. https://doi.org/10.1182/blood-2015-11-682906
Lu D., Zhao Y., Tawatao R., Cottam H.B., Sen M., Leoni L.M., Kipps T.J., Corr M., Carson D.A. Activation of the Wnt signaling pathway in chronic lymphocytic leukemia. Proc Natl Acad Sci USA. 2004; 101 (9): 3118–23. https://doi.org/10.1073/pnas.0308648100
Yu J., Chen L., Cui B., Widhopf G.F., 2nd, Shen Z., Wu R., Zhang L., Zhang S., Briggs S. P., Kipps T.J. Wnt5a induces ROR1/ROR2 heterooligomerization to enhance leukemia chemotaxis and proliferation. J. Clin. Invest. 2016; 126 (2): 585–98. https://doi.org/10.1172/JCI83535
High-level ROR1 associates with accelerated disease progression in chronic lymphocytic leukemia. PubMed. Accessed August 27, 2024. https://pubmed.ncbi.nlm.nih.gov/27815263/
Seke Etet P.F., Vecchio L., Nwabo Kamdje A.H. Interactions between bone marrow stromal microenvironment and B-chronic lymphocytic leukemia cells: any role for Notch, Wnt and Hh signaling pathways? Cell Signal. 2012; 24 (7): 1433–43. https://doi.org/10.1016/j.cellsig.2012.03.008
Decker S., Zirlik K., Djebatchie L., Hartmann D., Ihorst G., Schmitt-Graeff A., Herchenbach D. et al. Trisomy 12 and elevated GLI1 and PTCH1 transcript levels are biomarkers for Hedgehog-inhibitor responsiveness in CLL. Blood. 2012; 119 (4): 997–1007. https://doi.org/10.1182/blood-2011-06-359075
De Falco F., Sabatini R., Del Papa B., Falzetti F., Di Ianni M., Sportoletti P., Baldoni S. et al. Notch signaling sustains the expression of Mcl-1 and the activity of eIF4E to promote cell survival in CLL. Oncotarget. 2015; 6 (18): 16559–72. https://doi.org/10.18632/oncotarget.4116
Coelho V., Krysov S., Steele A., Sanchez Hidalgo M., Johnson P.W., Chana P.S., Packham G., Stevenson F.K., Forconi F. Identification in CLL of circulating intraclonal subgroups with varying B-cell receptor expression and function. Blood. 2013; 122 (15). https://doi.org/10.1182/blood-2013-02-485425
Burger J.A., Burger M., Kipps T.J. Chronic lymphocytic leukemia B cells express functional CXCR4 chemokine receptors that mediate spontaneous migration beneath bone marrow stromal cells. Blood. 1999; 94 (11). Accessed August 27, 2024. https://pubmed.ncbi.nlm.nih.gov/10572077/
Burger J.A., Tsukada N., Burger M., Zvaifler N.J., Dell’Aquila M., Kipps T.J. Blood-derived nurse-like cells protect chronic lymphocytic leukemia B cells from spontaneous apoptosis through stromal cell-derived factor-1. Blood. 2000; 96 (8): 2655–63.
Calissano C., Damle R.N., Marsilio S., Yan X.J., Yancopoulos S., Hayes G., Emson C. et al. Intraclonal complexity in chronic lymphocytic leukemia: fractions enriched in recently born/divided and older/quiescent cells. Mol Med Camb Mass. 2011; 17 (11–12). https://doi.org/10.2119/molmed.2011.00360
Pepper C., Buggins A.G., Jones C.H., Walsby E.J., Forconi F., Pratt G., Devereux S., Stevenson F.K., Fegan C. Phenotypic heterogeneity in IGHV-mutated CLL patients has prognostic impact and identifies a subset with increased sensitivity to BTK and PI3Kδ inhibition. Leukemia. 2015; 29 (3): 744–7. https://doi.org/10.1038/leu.2014.308
Juliusson G., Oscier D.G., Fitchett M., Ross F.M., Stockdill G., Mackie M.J., Parker A.C. et al. Prognostic subgroups in B-cell chronic lymphocytic leukemia defined by specific chromosomal abnormalities. N. Engl. J. Med. 1990; 323 (11): 720–4. https://doi.org/10.1056/NEJM199009133231105
Haferlach C., Dicker F., Schnittger S., Kern W., Haferlach T. Comprehensive genetic characterization of CLL: a study on 506 cases analysed with chromosome banding analysis, interphase FISH, IgV(H) status and immunophenotyping. Leukemia. 2007; 21 (12): 2442–51. https://doi.org/10.1038/sj.leu.2404935
Edelmann J., Holzmann K., Miller F., Winkler D., Bühler A., Zenz T., Bullinger L. et al. High-resolution genomic profiling of chronic lymphocytic leukemia reveals new recurrent genomic alterations. Blood. 2012; 120 (24): 4783–94. https://doi.org/10.1182/blood-2012-04-423517
Delgado J., Salaverria I., Baumann T., Martinez-Trillos A., Lee E., Jiménez L., Navarro A. et al. Genomic complexity and IGHV mutational status are key predictors of outcome of chronic lymphocytic leukemia patients with TP53 disruption. Haematologica. 2014; 99 (11): 231–4. https://doi.org/10.3324/haematol.2014.108365
Thompson P.A., Stingo F., Keating M.J., Ferrajoli A., Burger J.A., Wierda W.G., Kadia T.M., O'Brien S.M. Outcomes of patients with chronic lymphocytic leukemia treated with first-line idelalisib plus rituximab after cessation of treatment for toxicity. Cancer. 2016; 122 (16): 2505–11. https://doi.org/10.1002/cncr.30069
Baliakas P., Jeromin S., Iskas M., Puiggros A., Plevova K., Nguyen-Khac F., Davis Z. et al. Cytogenetic complexity in chronic lymphocytic leukemia: definitions, associations, and clinical impact. Blood. 2019; 133 (11): 1205–16. https://doi.org/10.1182/blood-2018-09-873083
Landgren O., Albitar M., Ma W., Abbasi F., Hayes R.B., Ghia P., Marti G.E., Caporaso N.E. B-cell clones as early markers for chronic lymphocytic leukemia. N. Engl. J. Med. 2009; 360 (7): 659–67. https://doi.org/10.1056/NEJMoa0806122
Criado I., Rodriguez-Caballero A., Gutiérrez M.L., Pedreira C.E., Alcoceba M., Nieto W., Teodosio C. et al. Low-count monoclonal B-cell lymphocytosis persists after seven years of follow up and is associated with a poorer outcome. Haematologica. 2018; 103 (7): 1198–208. https://doi.org/10.3324/haematol.2017.183954
Rawstron A.C., Bennett F.L., O'Connor S.J., Kwok M., Fenton J.A., Plummer M., de Tute R. et al. Monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia. N. Engl. J. Med. 2008; 359 (6): 575–83. https://doi.org/10.1056/NEJMoa075290
Rossi D., Spina V., Gaidano G. Biology and treatment of Richter syndrome. Blood. 2018; 131 (25): 2761–72. https://doi.org/10.1182/blood-2018-01-791376
Del Giudice I., Chiaretti S., Tavolaro S., De Propris M.S., Maggio R., Mancini F., Peragine N. et al. Spontaneous regression of chronic lymphocytic leukemia: clinical and biologic features of 9 cases. Blood. 2009; 114 (3): 638–46. https://doi.org/10.1182/blood-2008-12-196568
Barrio S., Shanafelt T.D., Ojha J., Chaffee K.G., Secreto C., Kortüm K.M., Pathangey S. et al. Genomic characterization of high-count MBL cases indicates that early detection of driver mutations and subclonal expansion are predictors of adverse clinical outcome. Leukemia. 2017; 31 (1): 170–6. https://doi.org/10.1038/leu.2016.172
Winkelmann N., Rose-Zerilli M., Forster J., Parry M., Parker A., Gardiner A., Davies Z. et al. Low frequency mutations independently predict poor treatment-free survival in early stage chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis. Haematologica. 2015; 100 (6): 237–239. https://doi.org/10.3324/haematol.2014.120238
Gruber M., Bozic I., Leshchiner I., Livitz D., Stevenson K., Rassenti L., Rosebrock D., Taylor-Weiner A. et al. Growth dynamics in naturally progressing chronic lymphocytic leukaemia. Nature. 2019; 570 (7762): 474–9. https://doi.org/10.1038/s41586-019-1252-x
Montserrat E., Sanchez-Bisono J., Viñolas N., Rozman C. Lymphocyte doubling time in chronic lymphocytic leukaemia: analysis of its prognostic significance. Br. J. Haematol. 1986; 62 (3): 567–75. https://doi.org/10.1111/j.1365-2141.1986.tb02969.x
Al-Sawaf O., Robrecht S., Bahlo J., Fink A.M., Cramer P., V Tresckow J., Lange E. et al. Richter transformation in chronic lymphocytic leukemia (CLL)-a pooled analysis of German CLL Study Group (GCLLSG) front line treatment trials. Leukemia. 2021; 35 (1): 169–76. https://doi.org/10.1038/s41375-020-0797-x
Fabbri G., Khiabanian H., Holmes A.B., Wang J., Messina M., Mullighan C.G., Pasqualucci L. et al. Genetic lesions associated with chronic lymphocytic leukemia transformation to Richter syndrome. J. Exp. Med. 2013; 210 (11): 2273–88. https://doi.org/10.1084/jem.20131448
