Figure 6

Combined ERK1 and ERK2 siRNA knockdown vs. proliferation. a H1944 cells were transfected with equal quantities of ERK1 siRNA and ERK2 siRNA for 48 h, and placed into fresh media for the indicated times up to an additional 72 h. The control consisted of NTC siRNA at the same total oligonucleotide concentration. Combined ERK1/2 knockdown led to 20–50% reduction in pERK1 levels and 50–75% reduction in pERK2 over the course of the 72 h. b The effect of combined ERK1/2 knockdown on H1944 cell proliferation was similar to that of ERK2 knockdown (Figure 4). Overall, the effects on growth were minimal except for a 13% decrease in proliferation of PTHrP-positive H1944 cells at 72 h. *P < 0.05 vs. control siRNA by paired t test.