1. The alternative RelB NF-κB subunit is a novel critical player in diffuse large B-cell lymphoma
- Author
-
Aurélie Montagne, Karen Leroy, Nathalie Faumont, Jean Feuillard, Jacqueline Lehmann-Che, Véronique Baud, Maria Chiara Maiuri, Hervé Tilly, Corinne Haioun, Thierry Jo Molina, Martial Caly, Davi Collares, Jean-Philippe Jais, Anne Vincent-Salomon, Christiane Copie-Bergman, J A Martinez-Climent, Stéphanie Nuan-Aliman, Didier Bordereaux, Leonardo Lordello, Bruno Tesson, Guido Kroemer, Benjamin Bonsang, Baptiste Eluard, Fabrice Jardin, Oussama Taoui, Isabelle Martins, and Nicolas Cagnard
- Subjects
Transcriptional Activation ,DNA damage ,Immunology ,Apoptosis ,Biology ,Biochemistry ,chemistry.chemical_compound ,immune system diseases ,hemic and lymphatic diseases ,Cell Line, Tumor ,Gene expression ,medicine ,Humans ,Transcription factor ,RELB ,Transcription Factor RelB ,NF-kappa B ,NF-κB ,Cell Biology ,Hematology ,CD79B ,medicine.disease ,Lymphoma ,Gene Expression Regulation, Neoplastic ,chemistry ,Cancer research ,Lymphoma, Large B-Cell, Diffuse ,Diffuse large B-cell lymphoma - Abstract
Diffuse large B-cell lymphoma (DLBCL) is the most frequent lymphoid malignancy affecting adults. The NF-κB transcription factor family is activated by 2 main pathways, the canonical and the alternative NF-κB activation pathway, with different functions. The alternative NF-κB pathway leads to activation of the transcriptionally active RelB NF-κB subunit. Alternative NF-κB activation status and its role in DLBCL pathogenesis remain undefined. Here, we reveal a frequent activation of RelB in a large cohort of DLBCL patients and cell lines, independently of their activated B-cell–like or germinal center B-cell–like subtype. RelB activity defines a new subset of patients with DLBCL and a peculiar gene expression profile and mutational pattern. Importantly, RelB activation does not correlate with the MCD genetic subtype, enriched for activated B-cell–like tumors carrying MYD88L265P and CD79B mutations that cooperatively activate canonical NF-κB, thus indicating that current genetic tools to evaluate NF-κB activity in DLBCL do not provide information on the alternative NF-κB activation. Furthermore, the newly defined RelB-positive subgroup of patients with DLBCL exhibits a dismal outcome after immunochemotherapy. Functional studies revealed that RelB confers DLBCL cell resistance to DNA damage–induced apoptosis in response to doxorubicin, a genotoxic agent used in the front-line treatment of DLBCL. We also show that RelB positivity is associated with high expression of cellular inhibitor of apoptosis protein 2 (cIAP2). Altogether, RelB activation can be used to refine the prognostic stratification of DLBCL and may contribute to subvert the therapeutic DNA damage response in a segment of patients with DLBCL.
- Published
- 2020