Barcelona Supercomputing Center, Carbó Meix, Anna, Guijarro, Francesca, Wang, Luojun, Grau, Marta, Royo, Romina, Barcelona Supercomputing Center, Carbó Meix, Anna, Guijarro, Francesca, Wang, Luojun, Grau, Marta, and Royo, Romina
The t(14;19)(q32;q13) often juxtaposes BCL3 with immunoglobulin heavy chain (IGH) resulting in overexpression of the gene. In contrast to other oncogenic translocations, BCL3 rearrangement (BCL3-R) has been associated with a broad spectrum of lymphoid neoplasms. Here we report an integrative whole-genome sequence, transcriptomic, and DNA methylation analysis of 13 lymphoid neoplasms with BCL3-R. The resolution of the breakpoints at single base-pair revealed that they occur in two clusters at 5’ (n=9) and 3’ (n=4) regions of BCL3 associated with two different biological and clinical entities. Both breakpoints were mediated by aberrant class switch recombination of the IGH locus. However, the 5’ breakpoints (upstream) juxtaposed BCL3 next to an IGH enhancer leading to overexpression of the gene whereas the 3’ breakpoints (downstream) positioned BCL3 outside the influence of the IGH and were not associated with its expression. Upstream BCL3-R tumors had unmutated IGHV, trisomy 12, and mutated genes frequently seen in chronic lymphocytic leukemia (CLL) but had an atypical CLL morphology, immunophenotype, DNA methylome, and expression profile that differ from conventional CLL. In contrast, downstream BCL3-R neoplasms were atypical splenic or nodal marginal zone lymphomas (MZL) with mutated IGHV, complex karyotypes and mutated genes typical of MZL. Two of the latter four tumors transformed to a large B-cell lymphoma. We designed a novel fluorescence in situ hybridization assay that recognizes the two different breakpoints and validated these findings in 17 independent tumors. Overall, upstream or downstream breakpoints of BCL3-R are mainly associated with two subtypes of lymphoid neoplasms with different (epi)genomic, expression, and clinicopathological features resembling atypical CLL and MZL, respectively., This study was supported by the “la Caixa" Foundation (CLLEvolution - LCF/PR/HR17/52150017 [HR17-00221LCF] and CLLSYSTEMS - LCF/PR/HR22/52420015 [HR22-00172] Health Research 2017 and 2022 Programs, to EC), the European Research Council (to EC and JIM-S) under the European Union’s Horizon 2020 research and innovation program (810287, BCLLatlas, to EC), Ministry of Science and Innovation (MCIN) /AEI/10.13039/501100011033/ and European Regional Development Fund “Una manera de hacer Europa” (PID2021-123054OB-I00 to EC) and the Generalitat de Catalunya Suport Grups de Recerca AGAUR (2021-SGR01172 to EC and 2021-SGR-01293 to SB). HP-A is a recipient of a pre-doctoral fellowship from the Spanish Ministry of Science, Innovation and Universities (FPU19/03110). MD-F acknowledges the research support from the AECC Scientific Foundation. FN acknowledges research support from the American Association for Cancer Research (2021 AACR-Amgen Fellowship in Clinical/Translational Cancer Research, 21-40-11-NADE), European Hematology Association (EHA Junior Research Grant 2021, RG-202012-00245), and Lady Tata Memorial Trust (International Award for Research in Leukemia 2021-2022, LADY_TATA_21_3223). EC is an Academia Researcher of the “Institució Catalana de Recerca i Estudis Avançats” (ICREA) of the Generalitat de Catalunya., Peer Reviewed, "Article signat per 45 autors/es: Anna Carbó-Meix, Francesca Guijarro, Luojun Wang, Marta Grau, Romina Royo, Gerard Frigola, Heribert Playa-Albinyana, Marco M. Bühler, Guillem Clot, Martí DuranFerrer, Junyan Lu, Isabel Granada, Maria-Joao Baptista, José-Tomás Navarro, Blanca Espinet, Anna Puiggros, Gustavo Tapia, Laura Bandiera, Gabriella De Canal, Emanuela Bonoldi, Fina Climent, Inmaculada Ribera-Cortada, Mariana Fernández-Caballero, Esmeralda de la Banda, Janilson do Nascimento, Alberto Pineda, Dolors Vela, María Rozman, Marta Aymerich, Charlotte Syrykh, Pierre Brousset, Miguel Perera, Lucrecia Yáñez, Jesús Xavier Ortin, Esperanza Tuset, Thorsten Zenz, James R. Cook, Steven H. Swerdlow, José I. Martín-Subero, Dolors Colomer, Estella Matutes, Sílvia Beà, Dolors Costa,Ferran Nadeu and Elías Campo", Postprint (published version)