Open AccessSpecific interactions of BCL-2 family proteins mediate sensitivity to BH3-mimetics in diffuse large B-cell lymphoma
Author(s) -
Victoria M. Smith,
Anna Dietz,
Kristina Henz,
Daniela Bruecher,
Ross A Jackson,
Lisa Kowald,
Sjoerd J. L. van Wijk,
Sandrine Jayne,
Salvador Macip,
Simone Fulda,
Martin J.S. Dyer,
Meike Vogler
Publication year - 2019
Publication title -
haematologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.782
H-Index - 142
eISSN - 1592-8721
pISSN - 0390-6078
DOI - 10.3324/haematol.2019.220525
Subject(s) - venetoclax , apoptosis , bcl xl , bcl 2 family , lymphoma , cancer research , bcl 2 associated x protein , chemistry , programmed cell death , cell culture , biology , chronic lymphocytic leukemia , microbiology and biotechnology , leukemia , immunology , caspase 3 , genetics , biochemistry
The BCL-2-specific inhibitor, ABT-199 (venetoclax) has exhibited remarkable clinical activity in nearly all cases of chronic lymphocytic leukemia. In contrast, responses are usually much less in diffuse large B-cell lymphoma (DLBCL), despite high level expression of BCL-2 in over 40% of cases, indicating that co-expression of related anti-apoptotic BCL-2 family proteins may limit the activity of ABT-199. We have investigated the roles of BCL-2 proteins in DLBCL cells using a panel of specific BCL-2 homology 3 (BH3)-mimetics and identified subgroups of these cells that exhibited marked and specific dependency on either BCL-2, BCL-X L or MCL-1 for survival. Dependency was associated with selective sequestration of the pro-apoptotic proteins BIM, BAX and BAK by the specific anti-apoptotic BCL-2 protein which was important for cellular survival. Sensitivity to BH3-mimetics was independent of genetic alterations involving the BCL-2 family and only partially correlated with protein expression levels. Treatment with ABT-199 displaced BAX and BIM from BCL-2, subsequently leading to BAK activation and apoptosis. In contrast, apoptosis induced by inhibiting BCL-X L with A1331852 was associated with a displacement of both BAX and BAK from BCL-X L and occurred independently of BIM. Finally, the MCL-1 inhibitor S63845 induced mainly BAX-dependent apoptosis mediated by a displacement of BAK, BIM and NOXA from MCL-1. In conclusion, our study indicates that in DLBCL, the heterogeneous response to BH3-mimetics is mediated by selective interactions between BAX, BAK and anti-apoptotic BCL-2 proteins.