Immunohistochemical analysis of STAT3 phosphorylation on Ser727 in normal lymphoid tissue, MCL, MGUS and MM samples and effects of CK2 inhibition on STAT3 and NF-κB phosphorylation.

<p>(A-D) Immunohistochemistry for phosphorylated STAT3 on Ser727 in normal reactive lymphoid tissue (A), neoplastic mantle cells from MCL patient (B), MGUS (C) and MM patient (D) (Immunoperoxidase stain, original magnifications 20x; pictures A and B have an insert at 100x magnification to show details). (E-H) Expression of phosphorylated STAT3 on Ser727 (p-STAT3 Ser727), total STAT3, phosphorylated NF-κB on Ser529 (p-NF-κB p65 Ser529), total NF-κB, in MM patient derived plasma cells (E), MM cell lines (F, G), MCL cell lines (H) treated with K27 (or CX-4945) and bortezomib (BZ in the figure) at different doses and the combination of CK2 and proteasome inhibitors for 6h (F, G left panel) or 18h (F, G right panel and H). β-actin was used as a loading control.