Cotransfection of c-Rel and CD40 enhances the proliferation of LBCL cells. (A) [³H] thymidine incorporation assay was performed after transfection of c-Rel (pCMV-c-Rel, 10 μg), CD40wt (pcDNA3.1/myc/his-CD40, 10 μg), and CD40NLSmut (pcDNA3.1/myc/his-CD40NLSmut, 10 μg) into LBCL-FN cells as indicated in the Figure. Twenty-four hours after transfection, live cells from each group were counted and the same number of live cells (20 000) was aliquoted and pulse labeled with [³H] thymidine overnight. Cells were harvested and signals were counted in a Beckman LS3800 liquid scintillation counter. Error bars indicate SD of triplicate samples. (B) Total cell lysis of each transfection group was subjected to Western blotting, and the expression of transfected as well as target gene products was detected by their specific antibodies. β-Actin was used as a loading control.