Figure 3.

Effects of ST2825 on the MYD88 signaling pathway in ABC DLBCL cells with the MYD88 L265P mutation. (A) ABC DLBCL lines (OCI-LY10 and TMD8) were treated with 10 µM ST2825 or DMSO for 6 h. The protein expression levels of phosphorylated BTK and IκB, total BTK and IκB, and β-actin were determined via western blotting. Upper: Western blot results are representative of three independent experiments; lower: Both the phosphorylated and total BTK (or IκB) expression levels were normalized to the β-actin control, and presented as a ratio of the phospho/total BTK (or IκB). (B) NF-κB-dependent luciferase activity in ABC DLBCL lines treated with ST2825 or DMSO for 24 h. Data are presented as the mean ± standard error of the mean from three independent experiments. (C) Secretion of IL-10 from ABC DLBCL cells treated for 24 h with ST2825 or DMSO. (D) Secretion of IFN-β from ABC DLBCL cells treated for 24 h with ST2825 or DMSO. Statistical analysis by one-way ANOVA with Dunnett's post hoc test. Data are presented as the mean ± standard deviation from experiments with three replicates. *P<0.05; **P<0.01; ***P<0.001. MYD88, myeloid differentiation primary response gene 88; DLBCA, diffuse large B-cell lymphoma; ABC, activated B cell; BTK, Bruton's tyrosine kinase; IĸB, inhibitor of nuclear factor kappa B kinase; IFN, interferon; p-, phosphorylated.