Fig. 6: RGS1 is a target of a p52 dependent cis-acting super-enhancer that drives myeloma progression via JNK and p38α signalling.

a Visualisation for the RGS1 locus encompassing proximal SEs. Tracks display: H3K27ac HiChIP contact matrix with differential loops annotated and coloured by log2 fold change; p52 ChIP-seq signal; ChIP-seq signal from control (brown) and p52 KD (orange) in KMS-11; SEs and dynamic H3K27ac peaks (orange = lost) called from KMS-11; loops indicated by arc annotation on control and p52 KD ChIP-seq tracks and coloured by counts per million; ChIP-seq signal from average of NF-κB+ (yellow) or NF-κB- (dark red) patients; equivalent ATAC-seq signals from KMS-11 and patients; SEs and constituent H3K27ac peaks classified by STABILO; gene track. b RGS1 expression in control and p52 knockdown in KMS-11 (left, n = 3 biological replicates per group) as well as MMRF groups (right): NF-κB+ (n = 331) and NF-κB- (n = 298). Normalised rLog transformed counts. Lower and upper hinges correspond to first and third quartiles. Central value corresponds to median. Whiskers extend to largest/smallest values no further than 1.5 x IQR (Interquartile range). 2-sided Wald test, adjusted for multiple comparisons (Benjamini-Hochberg) in DESeq2. c Representative western blot of RGS1 protein expression upon SE deletion, n = 2. d Cell adhesion to fibronectin. Points represent mean OD at 590 nm of technical triplicates. Mean ± SEM of 3 biological replicates per condition. Two-tailed t-test. e Assesment of apoptosis by FACS. Percentage of live cells (Annexin V-) and apoptotic cells (Annexin V + ) shown. Mean ± SEM of 3 biological replicates per condition. 2-way ANOVA. f Proliferation analyses by dye dilution. MFI (mean fluorescence intensity) calculated relative to day 0. Mean ± SEM of 3 biological replicates per condition. 2-way ANOVA. g Representative western blot showing activation level of JNK/c-Jun and p38α/p53/Bax axis of signalling cascade. Bands normalized with respect to GAPDH and displayed relative to WT+pLJM-GFP. Mean ± SEM of n = 3 biological replicates per condition. h Graphical summary of proposed p52/RGS1/JNK regulatory mechanism impacting MM. Created with BioRender.com i Mean tumour volume at D21 ± SEM, 5 mice per group. One way ANOVA. j Kaplan–Meier survival curves of mice xenografts. Survival evaluated from first day until sacrifice. N = 5 mice for each group, two-sided log-rank test. Source data are provided as a Source Data file.