Rationally designed BCL6 inhibitors target activated B cell diffuse large B cell lymphoma. Academic Article uri icon

Overview

abstract

  • Diffuse large B cell lymphomas (DLBCLs) arise from proliferating B cells transiting different stages of the germinal center reaction. In activated B cell DLBCLs (ABC-DLBCLs), a class of DLBCLs that respond poorly to current therapies, chromosomal translocations and amplification lead to constitutive expression of the B cell lymphoma 6 (BCL6) oncogene. The role of BCL6 in maintaining these lymphomas has not been investigated. Here, we designed small-molecule inhibitors that display higher affinity for BCL6 than its endogenous corepressor ligands to evaluate their therapeutic efficacy for targeting ABC-DLBCL. We used an in silico drug design functional-group mapping approach called SILCS to create a specific BCL6 inhibitor called FX1 that has 10-fold greater potency than endogenous corepressors and binds an essential region of the BCL6 lateral groove. FX1 disrupted formation of the BCL6 repression complex, reactivated BCL6 target genes, and mimicked the phenotype of mice engineered to express BCL6 with corepressor binding site mutations. Low doses of FX1 induced regression of established tumors in mice bearing DLBCL xenografts. Furthermore, FX1 suppressed ABC-DLBCL cells in vitro and in vivo, as well as primary human ABC-DLBCL specimens ex vivo. These findings indicate that ABC-DLBCL is a BCL6-dependent disease that can be targeted by rationally designed inhibitors that exceed the binding affinity of natural BCL6 ligands.

publication date

  • August 2, 2016

Research

keywords

  • Antineoplastic Agents
  • Drug Design
  • Gene Expression Regulation, Neoplastic
  • Lymphoma, Large B-Cell, Diffuse
  • Proto-Oncogene Proteins c-bcl-6

Identity

PubMed Central ID

  • PMC5004937

Scopus Document Identifier

  • 84987788606

Digital Object Identifier (DOI)

  • 10.1371/journal.pone.0090889

PubMed ID

  • 27482887

Additional Document Info

volume

  • 126

issue

  • 9