Fig. 2. The effect of PKC C2 domains on proliferation parameters of neuroblastoma cells. SK-N-BE(2) cells were transfected with expression vectors coding for C2 domains from the indicated PKC isoforms fused to EGFP and then cultured for 48 h in medium supplemented with 10% serum (A) or in the presence of 16 nM TPA in SHTE medium (B). BrdUrd incorporation ({blacksquare} in A and B) and detection of cyclin A with immunofluorescence ({square} in A) were used to estimate proliferating activity of transfected cells. Data are expressed as the percentage of transfected cells positive for either BrdUrd or cyclin A and are the mean ± SE of four (A) or three (B) separate experiments. Controls (-) are cells expressing EGFP only. Approximately 200 transfected cells identified by the presence of EGFP (A) or an average of around 100 transfected cells (B) were scored on each coverslip. Levels of significance: P < 0.05 (*) and P < 0.01 (**) compared with control cells (Student’s t test).