FIG. 2.
LMP2A or genistein inhibits BCR-induced tyrosine phosphorylation, DNA fragmentation, and cleavage PARP in Ramos cells. (A) Parental (P), vector control (V), and LMP2A-expressing (2A) Ramos cells (1 × 106/ml) were treated without (control [−]) or in the presence of 35 μg/ml anti-IgM antibody (αIgM Ab) for the indicated times (1, 5, or 10 min). (B) Cells (1 × 106/ml) were preincubated for 30 min with various concentrations of genistein, and then cells were treated with 35 μg/ml anti-IgM antibody for 10 min. Equal amounts of protein from the respective cells were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The levels of expression of phosphorylated tyrosine were determined by immunoblotting. (C) DNA fragmentation and (D) evaluation of cleavage of PARP. Cells (3 × 105/ml) were preincubated for 30 min with or without genistein, and cells were then treated with 35 μg/ml anti-IgM antibody. After 24 h of incubation, cell cycles and PARP cleavage were analyzed as described in the legend to Fig. 1. The amount of protein loaded in each lane was assessed by rehybridization of the filter with a specific antibody for human GAPDH.