Western blot analysis of CHK2 protein in NHLs and normal lymphoid tissues.

(A) There were 2 aggressive lymphomas (no. 790 and no. 1022) that lacked CHK2 protein expression. There were 3 additional tumors (no. 578, no. 577, and no. 1016) that showed low levels of expression, whereas the remaining samples had protein levels similar to those observed in normal tonsil. The HCT15 colon cancer cell line was used as negative control. (B) Normal reactive lymphoid tissues showed similar CHK2 protein expression levels, while in normal peripheral blood lymphocytes (PBLs) very low or absent CHK2 expression was detected. Normal spleen samples showed low expression of CHK2 protein with a particular pattern, probably related to phosphorylation differences. Expression of α-tubulin in the same samples used as a loading control is shown in the bottom panels.