Detection of early seeding of Richter transformation in chronic lymphocytic leukemia

Richter transformation (RT) is a paradigmatic evolution of chronic lymphocytic leukemia (CLL) into a very aggressive large B cell lymphoma conferring a dismal prognosis. The mechanisms driving RT remain largely unknown. We characterized the whole genome, epigenome and transcriptome, combined with si...

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Bibliographic Details
Authors: Nadeu, Ferran, Massoni-Badosa, Ramon, Ruiz Gil, Sara, Marchese, Domenica, 1986-, López Bigas, Núria, Gut, Ivo Glynne, Heyn, Holger, Campo, Elias
Format: article
Status:Published version
Publication Date:2022
Country:España
Institution:Universitat Pompeu Fabra
Repository:Repositorio Digital de la UPF
OAI Identifier:oai:repositori.upf.edu:10230/54720
Online Access:http://hdl.handle.net/10230/54720
http://dx.doi.org/10.1038/s41591-022-01927-8
Access Level:Open access
Keyword:B-cell lymphoma
Cancer epigenetics
Cancer genomics
Chronic lymphocytic leukaemia
Tumour heterogeneity
Description
Summary:Richter transformation (RT) is a paradigmatic evolution of chronic lymphocytic leukemia (CLL) into a very aggressive large B cell lymphoma conferring a dismal prognosis. The mechanisms driving RT remain largely unknown. We characterized the whole genome, epigenome and transcriptome, combined with single-cell DNA/RNA-sequencing analyses and functional experiments, of 19 cases of CLL developing RT. Studying 54 longitudinal samples covering up to 19 years of disease course, we uncovered minute subclones carrying genomic, immunogenetic and transcriptomic features of RT cells already at CLL diagnosis, which were dormant for up to 19 years before transformation. We also identified new driver alterations, discovered a new mutational signature (SBS-RT), recognized an oxidative phosphorylation (OXPHOS)high-B cell receptor (BCR)low-signaling transcriptional axis in RT and showed that OXPHOS inhibition reduces the proliferation of RT cells. These findings demonstrate the early seeding of subclones driving advanced stages of cancer evolution and uncover potential therapeutic targets for RT.