RNA and protein expression changes after BCR crosslinking. (A) Temporal expression of 3 representative genes (DUSP1, EGR2, NFκB1) in healthy B cells and CLL B cells assessed by gene expression profile and by RQ-PCR analysis. (B) Immunoblot analysis of NFκB1 and DUSP1 proteins in representative CLL sample. For immunoblot analysis, cell lysates were prepared from negatively isolated fresh primary B CLL cells (US or S) at 3 to 4 different time points after BCR stimulation (60, 210, and 390 minutes and 16 hours). Thirty micrograms of protein lysate from each sample was loaded onto a separate lane of SDS-polyacrylamide gel. The immunoblot was probed with anti-NFκB1 antibody to detect NFκB1 p50 protein and its p105 precursor protein (labeled arrows, left). Blots were reprobed with Tim 23 or GAPDH antibody as control (labeled arrow, bottom). The molecular mass of protein standards is shown.