In:
Blood, American Society of Hematology, Vol. 114, No. 22 ( 2009-11-20), p. 1271-1271
Abstract:
Abstract 1271 Poster Board I-293 Diffuse large B cell lymphoma (DLBCL) is the most common type of lymphoma in humans. The aggressive activated B cell-like (ABC) subtype of DLBCL is characterized by constitutive NF-κB activity and requires signals from CARD11, BCL10 and the paracaspase MALT1 for survival. CARD11, BCL10 and MALT1 are scaffold proteins that normally associate upon antigen receptor ligation. Signal-induced CARD11/BCL10/MALT1 (CBM) complexes couple upstream events to IKK/NF-κB activation. MALT1 possesses in addition a recently recognized proteolytic activity that cleaves and inactivates the negative NF-κB regulator A20 and BCL10 upon antigen receptor ligation. Yet, the relevance of MALT1 proteolytic activity for malignant cell growth is unknown. Here we demonstrate pre-assembled CBM complexes and constitutive proteolysis of the two known MALT1 substrates in ABC-DLBCL but not in germinal center B cell-like (GCB) DLBCL. ABC-DLBCL cell treatment with a MALT1 protease inhibitor blocks A20 and BCL10 cleavage, reduces NF-κB activity and decreases the expression of NF-κB targets genes. Finally, MALT1 paracaspase inhibition results in death and growth retardation selectively in ABC-DLBCL cells. Thus, our results indicate a growth-promoting role for MALT1 paracaspase activity in ABC-DLBCL and suggest that a pharmacological MALT1 protease inhibition could be a promising approach for lymphoma treatment. Disclosures No relevant conflicts of interest to declare.
Type of Medium:
Online Resource
ISSN:
0006-4971
,
1528-0020
DOI:
10.1182/blood.V114.22.1271.1271
Language:
English
Publisher:
American Society of Hematology
Publication Date:
2009
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7
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