B cell lymphoma 6 (BCL6) is a transcriptional repressor critical for the development and maintenance of germinal centers (GCs), which are required for generation of an effective humoral immune response. Genomic aberrations of BCL6, including mutations and translocations that occur during the GC reaction, as well as alterations of genes that regulate BCL6 expression, lead to sustained activity of BCL6, which promotes the development of GC-derived lymphomas. Since many types of B cell non-Hodgkin lymphomas (B-NHL) arise from neoplastic transformation of GC B cells and a high proportion harbor genetic lesions that deregulate BCL6 expression, inhibition of BCL6 has emerged as an attractive therapeutic strategy for lymphomas. Areas covered: This review examines the rationale for and challenges in therapeutic targeting of BCL6 in lymphomas. We describe approaches that have been used and are currently being considered for inhibition of BCL6. Expert opinion: Several BCL6 inhibiting agents, including peptidomimetics, small molecules, and natural compounds, most of which target the BTB domain of the protein at the corepressor binding site, have been developed with demonstration of anti-lymphoma activity in preclinical models. Future clinical trials will be important to investigate the efficacy of targeting BCL6 in B-NHL (and other neoplasms), particularly in combination with other therapies.
