FBXO11 deletion in BL cell lines leads to BCL6 protein stabilization. (A) BLC6 stability in human BL lines in which FBXO11 is knocked out. Representative western blot showing BCL6 protein expression in 3 independent FBXO11 KO RAJI cell lines (clone #1 obtained with sgRNA#1, clones #2 and #3 obtained with sgRNA#2; supplemental Figure 5B-E) after treatment with CHX for the indicated times. FARAGE cell line, which is homozygous for deletion of the FBXO11 gene, was used as control for BCL6 stability. One representative experiment of 3 independently performed experiments is shown. (B) Representative western blot showing BCL6 protein expression in WT or FBXO11-KO DAUDI cell line after treatment with CHX for the indicated times. β-actin was used as a loading control. One representative experiment of 3 independently performed experiments is shown. (C) Degradation kinetics of BCL6 in BL WT or FBXO11-KO cells. BCL6 abundance was measured from western blot gels as in (A-B) using ImageJ software and normalized for the β-actin intensity of the corresponding lane. (D) Quantitative real-time PCR expression analysis of the BCL6 target genes DUSP5, CDKN1A, and CD69 mRNA in RAJI and 2 FBXO11-KO RAJI cell lines (#1 and #2). Data are mean ± standard deviation. (E) Hierarchical clustering (Euclidean distance, average linkage) of 172 genes detected as differentially expressed between the FBXO11-WT or -KO RAJI cell lines. (F) Analysis of genes detected as differentially expressed between WT cell lines and KO clones. Forty-seven of 172 differentially expressed genes can be connected to each other using Ingenuity Pathway Analysis (QIAGEN IPA) in a BCL6-centered network. **P < .01, ***P < .001, unpaired 2-tailed Student t test.