Project description:This SuperSeries is composed of the following subset Series: GSE31421: Cereblon expression is required for the anti-myeloma activity of lenalidomide and pomalidomide [expression profiling] GSE31451: Cereblon expression is required for the anti-myeloma activity of lenalidomide and pomalidomide [aCGH] Refer to individual Series
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:Multiple myeloma is a genetically heterogeneous disease of plasma cells. The thalidomide analog lenalidomide is a mainstay in the treatment of multiple myeloma and is used in combination with other drugs such as corticosteroids, chemotherapy and proteasome inhibitors, achieving high remission rates. However, most patients relapse due to acquired resistance of the malignant cells. Genetic analyses have revealed mutations in CRBN, the target of all IMiDs, as a resistance mechanism in 10% of patients, while for the majority of cases, the mechanism of resistance is unknown. Here, we performed integrated global quantitative tandem mass tag (TMT)-based proteomic and phosphoproteomic analyses and RNA sequencing in five paired pre-treatment and relapse samples from multiple myeloma patients. These analyses revealed proteins highly upregulated at relapse, including TRIP13, RRM1 and CDK6, which was not reflected on the RNA expression level. Overexpression of CDK6 in multiple myeloma cell lines reduced sensitivity to lenalidomide and pomalidomide in a kinase-dependent fashion. CDK6 inactivation by palbociclib or a CDK6-specific proteolysis targeting chimera (PROTAC) plus lenalidomide or pomalidomide was highly synergistic. Proteomic analyses in cell lines revealed that CDK6 inhibition reverses a complex protein resistance signature including RRM1 and TRIP13 and in combination with IMiDs promotes metabolic remodeling and c-MYC downregulation . In conclusion, our global proteomic analyses identified CDK6 upregulation as a drug target to overcome lenalidomide resistance in multiple myeloma.
Project description:Treatment for acute myeloid leukemia (AML) remains suboptimal and many patients remain refractory or relapse upon standard chemotherapy based on nucleoside analogs plus anthracyclines. The crosstalk between AML cells and the bone marrow (BM) stroma is a major mechanism underlying therapy resistance in AML. Lenalidomide and pomalidomide, a new generation immunomodulatory drugs (IMiDs), possess pleiotropic anti-leukemic properties including potent immune-modulating effects and are commonly used in hematological malignances associated with intrinsic dysfunctional BM such as myelodysplastic syndromes and multiple myeloma. Whether IMiDs may improve the efficacy of current standard treatment in AML remains understudied. Here, we have exploited in vitro and in vivo preclinical AML models to analyze whether IMiDs potentiate the efficacy of AraC/Iradubicin (standard AML chemotherapy) by interfering with the BM stroma-mediated chemoresistance. We report that lenalidomide and pomalidomide have cytotoxic effects on neither AML cells nor BM-MSCs, but they increase the immunosuppressive/immunomodulatory properties of BM-MSCs. When combined with AraC and Idarubicin, IMiDs fail to circumvent BM stroma-mediated resistance of AML cells in vitro and in vivo but induce robust extramedullary mobilization of AML cells. When administered as a single agent, lenalidomide highly mobilizes AML cells, but not healthy CD34+ cells, to peripheral blood (PB) likely through specific downregulation of CXCR4 in AML blasts. Global gene expression profiling supports a migratory/mobilization gene signature in lenalidomide-treated AML blasts but not in CD34+ cells. Collectively, IMiDs mobilize AML blasts to PB through downregulation of CXCR4 but do not improve AraC/Idarubicin activity in a preclinical model of AML.