A genome-scale CRISPR-Cas9 screening in myeloma cells identifies regulators of immunomodulatory drug sensitivity

• Published in: Leukemia 2019-01, Vol.33 (1), p.171-180
• Main Authors: Liu, Jiye, Song, Tianyu, Zhou, Wenrong, Xing, Lijie, Wang, Su, Ho, Matthew, Peng, Zhengang, Tai, Yu-Tzu, Hideshima, Teru, Anderson, Kenneth C., Cang, Yong
• Format: Article
• Language: English
• Subjects: 42/109; 45/41; 45/43; 631/67/1059/2326; 631/67/1990/804; 82/1; 96/2; 96/47; 96/95; Adaptor Proteins, Signal Transducing; Antineoplastic Agents - pharmacology; Biomarkers, Tumor - genetics; Biomarkers, Tumor - metabolism; Bortezomib - pharmacology; Cancer cells; Cancer genetics; Cancer Research; COP9 Signalosome Complex - antagonists & inhibitors; COP9 Signalosome Complex - genetics; COP9 Signalosome Complex - metabolism; CRISPR; CRISPR-Cas Systems; Critical Care Medicine; Cullin; Cyclopentanes - pharmacology; Cytotoxicity; Deactivation; Degradation; DNA binding proteins; Drug resistance; Drugs; Enzyme Inhibitors - pharmacology; Enzymes; Gene expression; Gene Expression Regulation, Neoplastic; Genomes; Genomics; Hematology; Humans; Ikaros Transcription Factor - genetics; Ikaros Transcription Factor - metabolism; Immunologic factors; Immunologic Factors - pharmacology; Immunomodulation; Immunomodulators; Inhibitors; Intensive; Internal Medicine; Lenalidomide; Ligases; Medical screening; Medicine; Medicine & Public Health; Multiple myeloma; Multiple Myeloma - drug therapy; Multiple Myeloma - genetics; Multiple Myeloma - pathology; Oncology; Peptide Hydrolases - genetics; Peptide Hydrolases - metabolism; Prognosis; Proteasome inhibitors; Proteasomes; Proteolysis; Pyrimidines - pharmacology; Regulators; Sensitivity; Sensitivity enhancement; Toxicity; Transcription factors; Tumor Cells, Cultured; Ubiquitin; Ubiquitin-protein ligase; Ubiquitin-Protein Ligases; Ubiquitination
• ISSN: 0887-6924; 1476-5551
• DOI: 10.1038/s41375-018-0205-y

Immunomodulatory drugs (IMiDs) including lenalidomide and pomalidomide bind cereblon (CRBN) and activate the CRL4 CRBN ubiquitin ligase to trigger proteasomal degradation of the essential transcription factors IKZF1 and IKZF3 and multiple myeloma (MM) cytotoxicity. We have shown that CRBN is also targeted for degradation by SCF Fbxo7 ubiquitin ligase. In the current study, we explored the mechanisms underlying sensitivity of MM cells to IMiDs using genome-wide CRISPR-Cas9 screening. We validate that CSN9 signalosome complex, a deactivator of Cullin-RING ubiquitin ligase, inhibits SCF Fbxo7 E3 ligase-mediated CRBN degradation, thereby conferring sensitivity to IMiDs; conversely, loss of function of CSN9 signalosome activates SCF Fbxo7 complex, thereby enhancing degradation of CRBN and conferring IMiD resistance. Finally, we show that pretreatment with either proteasome inhibitors or NEDD8 activating enzyme (NAE) inhibitors can abrogate degradation and maintain levels of CRBN, thereby enhancing sensitivity to IMiDs. These studies therefore demonstrate that CSN9 signalosome complex regulates sensitivity to IMiDs by modulating CRBN expression.