A, LNCaP cells treated with different concentrations of B2G2 (30, 40 and 50 μM), whole cell lysates were prepared at indicated time-points and analyzed for p-ERK1/2 by immunoblotting. Membranes were stripped and re-probed for total ERK1/2 and β-actin. B, LNCaP cells were treated with B2G2 (50 μM), whole cell lysates were prepared at 1, 3, 6, 9, 12, 15, 18 and 24 h post-treatment and analyzed for p-ERK1/2 level by immunoblotting. Membranes were stripped and re-probed for total ERK1/2 and β-actin. C–D, LNCaP cells were treated with PD98059 (10, 25 and 50 μM) 15 min prior to B2G2 (50 μM) treatment and whole cell lysates were prepared at 24 h post-treatment and analyzed for p-ERK1/2 and cleaved PARP (cl PARP); membranes were stripped and re-probed for total ERK1/2 and β-actin (C); at the same time-point total cell number and percentage cell death were also determined by trypan blue exclusion assay (D). Data are expressed as of mean ± SEM (n=3) for each treatment. * P < 0.05, significant with respect to control group. # P < 0.05, significant with respect to the B2G2-treated group. E, LNCaP cells were treated with NAC (10 mM) 15 min prior to B2G2 (50 μM) treatment, whole cell lysates were prepared at 6 and 9 h post-treatment and analyzed for p-ERK1/2 by immunoblotting. Membranes were stripped and re-probed for total ERK1/2 and β-actin. F, LNCaP cells were treated with NAC (10 mM) or compound C (20 μM) prior to B2G2 (50 μM) treatment, whole cell lysates were prepared at 24 h and analyzed for cl PARP. Membrane was stripped and re-probed for β-actin.