Figure 1. Resistance to dBET6 by Dysregulation of CRBN and Its Interactors/Regulators.

(A) dBET6 dose-response curves (CellTiter-Glo [CTG] assays, 48 h) for pools of MM.1S cells that survived repeated dBET6 treatments during the long-term genome-scale CRISPR gene editing screen versus dBET6-naive cells (2-way ANOVA; p < 0.05 in terms of drug dose and p < 0.05 in terms of status of prior treatment with dBET6 or no treatment).

(B) Average log₂ fold change (log₂FC) of normalized read counts for sgRNAs against CRBN and several of its interactors after repeated dBET6 treatments during the long-term genome-scale CRISPR gene editing screen.

(C and D) MM.1S-Cas9+ cells transduced with individual sgRNAs for COPS7B and COPS8 (versus control sgRNAs) were tested for in vitro response to dBET6 (48 h; 2-way ANOVA; p < 0.05 in terms of drug dose and p < 0.05 in terms of status of transduction with five of the sgRNAs for COPS7B or three sgRNAs for COPS8 versus non-targeting (NT) control sgRNAs).

(E) MM cell lines known to express low but detectable CRBN levels constitutively (OPM1 and OCI-My5) or after transduction with shRNAs against CRBN (KMS11, OPM2) were tested for their in vitro response to dBET6 (48 h).

(F) dBET6 dose-response curves (72 h) for MM.1S-Cas9+ cells transduced with sgRNAs against CRBN (MM.1S CRBN^−/−), COPS7B, COPS2, COPS8, or non-targeting control sgRNAs.

(A) and (C)–(E) depict averages ± SE of 3 independent experiments (CTG) for each panel, with triplicates per condition. (F) depicts averages ± SE from a single experiment with triplicates per condition.