Cereblon is a direct protein target for immunomodulatory and antiproliferative activities of lenalidomide and pomalidomide

Abstract

Thalidomide and the immunomodulatory drug, lenalidomide, are therapeutically active in hematological malignancies. The ubiquitously expressed E3 ligase protein cereblon (CRBN) has been identified as the primary teratogenic target of thalidomide. Our studies demonstrate that thalidomide, lenalidomide and another immunomodulatory drug, pomalidomide, bound endogenous CRBN and recombinant CRBN–DNA damage binding protein-1 (DDB1) complexes. CRBN mediated antiproliferative activities of lenalidomide and pomalidomide in myeloma cells, as well as lenalidomide- and pomalidomide-induced cytokine production in T cells. Lenalidomide and pomalidomide inhibited autoubiquitination of CRBN in HEK293T cells expressing thalidomide-binding competent wild-type CRBN, but not thalidomide-binding defective CRBNYW/AA. Overexpression of CRBN wild-type protein, but not CRBNYW/AA mutant protein, in KMS12 myeloma cells, amplified pomalidomide-mediated reductions in c-myc and IRF4 expression and increases in p21WAF-1 expression. Long-term selection for lenalidomide resistance in H929 myeloma cell lines was accompanied by a reduction in CRBN, while in DF15R myeloma cells resistant to both pomalidomide and lenalidomide, CRBN protein was undetectable. Our biophysical, biochemical and gene silencing studies show that CRBN is a proximate, therapeutically important molecular target of lenalidomide and pomalidomide.

Impact of prior treatment and depth of response on survival in MM-003, a randomized phase 3 study comparing pomalidomide plus low-dose dexamethasone versus high-dose dexamethasone in relapsed/refractory multiple myeloma

“…This is consistent with in vitro data demonstrating antimyeloma effects of POM on LEN-resistant MM cell lines. 25,26 These results support the use of immunomodulatory agents in succession, and show that prior LEN treatment should not preclude the use of POM.…”

Aiolos Overexpression in Systemic Lupus Erythematosus B Cell Subtypes and BAFF-Induced Memory B Cell Differentiation Are Reduced by CC-220 Modulation of Cereblon Activity

“…Similar to lenalidomide and pomalidomide, which bind to CRBN, a critical component of a ubiquitin E3 CRL4 CRBN complex (120,121), CC-220 binds to CRBN to promote recruitment of Ikaros and Aiolos to CRL4 CRBN and the subsequent enhancement of the ubiquitination and degradation of these transcription factors (55-57). Ikaros and Aiolos are members of the Ikaros family of zinc-finger transcription factors crucial for the function of mature B cells in the periphery, and required for the generation and survival of high-affinity bone marrow plasma cells (60)(61)(62).…”

Epigenetic regulation of Kcna3 -encoding Kv1.3 potassium channel by cereblon contributes to regulation of CD4 + T-cell activation

“…T-cell activation | CRBN | Kv1.3 | calcium flux | potassium flux R ecent studies have identified cereblon (CRBN) as a thalidomidebinding protein (1,2). CRBN is expressed in the cytoplasm, nucleus, and peripheral membranes of a wide variety of cells and tissues (1,(3)(4)(5).…”