Project description:The precise molecular mechanism of action and targets through which thalidomide and related immunomodulatory drugs (IMiDs) exert their anti-tumor effects remains unclear. We investigated the role of cereblon (CRBN), a primary teratogenic target of thalidomide, in the anti-myeloma activity of IMiDs. CRBN depletion is initially cytotoxic to human myeloma cells but surviving cells with stable CRBN depletion become highly resistant to both lenalidomide and pomalidomide, but not to the unrelated drugs bortezomib, dexamethasone and melphalan. Acquired deletion of CRBN was found to be the primary genetic event differentiating isogenic MM1.S cell lines cultured to be sensitive or resistant to lenalidomide and pomalidomide. Gene expression changes induced by lenalidomide were dramatically suppressed in the presence of CRBN depletion further demonstrating that CRBN is required for lenalidomide activity. Downstream targets of CRBN include interferon regulatory factor 4 (IRF4) previously reported to also be a target of lenalidomide. Patients exposed to and putatively resistant to lenalidomide had lower CRBN levels in paired samples before and after therapy. In summary, CRBN is an essential requirement for IMiD activity, and a possible biomarker for the clinical assessment of anti-myeloma efficacy. We included 15 samples from multiple myeloma cell lines.
Project description:The precise molecular mechanism of action and targets through which thalidomide and related immunomodulatory drugs (IMiDs) exert their anti-tumor effects remains unclear. We investigated the role of cereblon (CRBN), a primary teratogenic target of thalidomide, in the anti-myeloma activity of IMiDs. CRBN depletion is initially cytotoxic to human myeloma cells but surviving cells with stable CRBN depletion become highly resistant to both lenalidomide and pomalidomide, but not to the unrelated drugs bortezomib, dexamethasone and melphalan. Acquired deletion of CRBN was found to be the primary genetic event differentiating isogenic MM1.S cell lines cultured to be sensitive or resistant to lenalidomide and pomalidomide. Gene expression changes induced by lenalidomide were dramatically suppressed in the presence of CRBN depletion further demonstrating that CRBN is required for lenalidomide activity. Downstream targets of CRBN include interferon regulatory factor 4 (IRF4) previously reported to also be a target of lenalidomide. Patients exposed to and putatively resistant to lenalidomide had lower CRBN levels in paired samples before and after therapy. In summary, CRBN is an essential requirement for IMiD activity, and a possible biomarker for the clinical assessment of anti-myeloma efficacy. We included two isogenic MM1.S cell lines, which differ in the sensibiligy to lenalidomide. We included MM1.S and MM1.S res, which were sensitive and resistant to lenalidomide, respectively.
Project description:The precise molecular mechanism of action and targets through which thalidomide and related immunomodulatory drugs (IMiDs) exert their anti-tumor effects remains unclear. We investigated the role of cereblon (CRBN), a primary teratogenic target of thalidomide, in the anti-myeloma activity of IMiDs. CRBN depletion is initially cytotoxic to human myeloma cells but surviving cells with stable CRBN depletion become highly resistant to both lenalidomide and pomalidomide, but not to the unrelated drugs bortezomib, dexamethasone and melphalan. Acquired deletion of CRBN was found to be the primary genetic event differentiating isogenic MM1.S cell lines cultured to be sensitive or resistant to lenalidomide and pomalidomide. Gene expression changes induced by lenalidomide were dramatically suppressed in the presence of CRBN depletion further demonstrating that CRBN is required for lenalidomide activity. Downstream targets of CRBN include interferon regulatory factor 4 (IRF4) previously reported to also be a target of lenalidomide. Patients exposed to and putatively resistant to lenalidomide had lower CRBN levels in paired samples before and after therapy. In summary, CRBN is an essential requirement for IMiD activity, and a possible biomarker for the clinical assessment of anti-myeloma efficacy.
Project description:The precise molecular mechanism of action and targets through which thalidomide and related immunomodulatory drugs (IMiDs) exert their anti-tumor effects remains unclear. We investigated the role of cereblon (CRBN), a primary teratogenic target of thalidomide, in the anti-myeloma activity of IMiDs. CRBN depletion is initially cytotoxic to human myeloma cells but surviving cells with stable CRBN depletion become highly resistant to both lenalidomide and pomalidomide, but not to the unrelated drugs bortezomib, dexamethasone and melphalan. Acquired deletion of CRBN was found to be the primary genetic event differentiating isogenic MM1.S cell lines cultured to be sensitive or resistant to lenalidomide and pomalidomide. Gene expression changes induced by lenalidomide were dramatically suppressed in the presence of CRBN depletion further demonstrating that CRBN is required for lenalidomide activity. Downstream targets of CRBN include interferon regulatory factor 4 (IRF4) previously reported to also be a target of lenalidomide. Patients exposed to and putatively resistant to lenalidomide had lower CRBN levels in paired samples before and after therapy. In summary, CRBN is an essential requirement for IMiD activity, and a possible biomarker for the clinical assessment of anti-myeloma efficacy.
Project description:Cereblon (CRBN), a substrate receptor of the E3 ubiquitin ligase complex CRL4CRBN, is the target of the immunomodulatory drugs lenalidomide and pomalidomide. Recently, it was demonstrated that binding of these drugs to CRBN promotes the ubiquitination and subsequent degradation of two common substrates, transcription factors Aiolos and Ikaros. Here we report that the pleiotropic pathway modifier CC-122, a new chemical entity termed pleiotropic pathway modifier binds CRBN and promotes degradation of Aiolos and Ikaros in diffuse large B-cell lymphoma (DLBCL) and T cells in vitro, in vivo and in patients, resulting in both cell autonomous as well as immunostimulatory effects. In DLBCL cell lines, CC-122-induced degradation or shRNA mediated knockdown of Aiolos and Ikaros correlates with increased transcription of interferon stimulated genes (ISGs) independent of interferon α, β, γ production and/or secretion and results in apoptosis in both ABC and GCB-DLBCL cell lines. Our results provide mechanistic insight into the cell of origin independent anti-lymphoma activity of CC-122, in contrast to the ABC subtype selective activity of lenalidomide. Microarray analysis of the OCI-LY10 activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL) cell line treated with the compound CC-122 for 18 hours
Project description:To dissect the roles of ARID2 and Aiolos in pomalidomide-induced transcriptional changes, we performed mRNA-sequencing of MM.1S cells expressing shRNA against ARID2 or Aiolos and compared them with MM.1S cells that were treated with pomalidomide for 24, 48, or 72 hours.
Project description:IMR32 cells stably expressing AGIA-AirID-CRBN or AGIA-TurboID-CRBN were treated with DMSO or 10 µM pomalidomide in the presence of 10 µM biotin and 5 µM MG132 for 2 h in three biological replicates. After tryptic digestion, biotinylated peptides were enriched with Tamavidin 2-REV and analyzed by LC-MS/MS analysis.
Project description:Lenalidomide is a therapeutically active compound that binds to E3 ubiquitin ligase recruiter cereblon (CRBN) and induces cytotoxicity. We have identified eukaryotic translation initiation factor 2 subunit C2 (EIF2C2) as a new member of CRBN-downstream binding protein that plays an important role in microRNA (miRNA) maturation and function. The treatment of immunomodulatory drug (IMiD)-sensitive multiple myeloma (MM) cells with lenalidomide altered the steady-state levels of CRBN, EIF2C2 and miRNAs and induced apoptosis. However, although the treatment of IMiD-resistant MM cells with lenalidomide altered the steady-state levels of CRBN, EIF2C2 and miRNAs, but did not massively induce apoptosis. In contrast, silencing of EIF2C2 with its small hairpin RNA significantly altered the levels of miRNAs and induced apoptosis regardless of whether those cells are sensitive or resistant to IMiDs. Therefore, EIF2C2 could be considered as a new drug target for overcoming IMiDs resistance in MM cells. To find the role of EIF2C2 in MM cell growth, OCI-My5 cell lines My5/LV and My5/CRBN, with low and high CRBN expression, respectively, were treated 12 different ways. The steady-state levels of miRNAs between (1) My5/LV, EIF2C2-shRNA-treated My5/LV and EIF2C2-cDNA-treated My5/LV cells, (2) My5/CRBN, EIF2C2-shRNA-treated My5/CRBN and EIF2C2-cDNA-treated My5/CRBN cells, (3) My5/LV cells, My5/LV cells treated with 10 µM lenalidomide for 72 hours or 120 hours, and EIF2C2-cDNA-treated My5/LV cells treated with 10 µM lenalidomide for 72 hours, and (4) My5/CRBN cells, My5/CRBN cells treated with 10 µM lenalidomide for 72 hours or 120 hours, and EIF2C2-cDNA-treated My5/CRBN cells treated with 10 µM lenalidomide for 72 hours, were compared in this array.