The BLIMP1—EZH2 nexus in a non-Hodgkin lymphoma

• Published in: Oncogene
• Main Authors: Harðardóttir, Ingibjörg, Anderson, Kimberley Jade, Ósvaldsdóttir, Árný Björg, Atzinger, Birgit, Traustadóttir, Gunnhildur Ásta, Jensen, Kirstine Nolling, Lárusdóttir, Aðalheiður Elín, Bergþórsson, Jón Þór, Magnúsdóttir, Erna
• Other Authors: Clinical Laboratory Services, Diagnostics and Blood Bank, Faculty of Medicine, Landspitali - The National University Hospital of Iceland, University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: Náttúrufræðingar; Molecular Biology; Genetics; Cancer Research; Iceland
• Online Access: https://hdl.handle.net/20.500.11815/3611; https://doi.org/10.1038/s41388-020-1347-8

Funding Information: Funding This work was supported by project grants from the Icelandic Research Fund (grant no. 140950-051) and the Icelandic Cancer Society, a doctoral fellowship from the University of Iceland, and grant from the University of Iceland Eggertssjodur and funds from the COST Project EpiChemBio. Publisher Copyright: © 2020, The Author(s), under exclusive licence to Springer Nature Limited. Waldenström’s macroglobulinemia (WM) is a non-Hodgkin lymphoma, resulting in antibody-secreting lymphoplasmacytic cells in the bone marrow and pathologies resulting from high levels of monoclonal immunoglobulin M (IgM) in the blood. Despite the key role for BLIMP1 in plasma cell maturation and antibody secretion, its potential effect on WM cell biology has not yet been explored. Here we provide evidence of a crucial role for BLIMP1 in the survival of cells from WM cell line models and further demonstrate that BLIMP1 is necessary for the expression of the histone methyltransferase EZH2 in both WM and multiple myeloma cell lines. The effect of BLIMP1 on EZH2 levels is post-translational, at least partially through the regulation of proteasomal targeting of EZH2. Chromatin immunoprecipitation analysis and transcriptome profiling suggest that the two factors co-operate in regulating genes involved in cancer cell immune evasion. Co-cultures of natural killer cells and cells from a WM cell line further suggest that both factors participate in immune evasion by promoting escape from natural killer cell-mediated cytotoxicity. Together, the interplay of BLIMP1 and EZH2 plays a vital role in promoting the survival of WM cell lines, suggesting a role for the two factors in Waldenström’s macroglobulinaemia. Peer reviewed