Figure 2.

Cell counts and signaling upon p38α/β inhibition in vitro. The experiments shown are representative experiments of at least two repetitions. (a) REH (left panel), 697 (middle panel) and SUP-B15 cells (right panel) were incubated with 10 μM SB203580 (SB) or BIRB-796 (BIRB) for 72 h. The number of viable cells was counted using standard Trypan blue exclusion. *P<0.05; NS, not significant; t-test. (b) REH (left panel) and 697 cells (right panel) were incubated with ascending concentrations of BIRB-796 (upper panels) or SB203580 (lower panels) for 48 h. Dimethyl sulfoxide (0 μM lanes) was used as a vehicle control. Cells were either directly lysed (− AIM) or stimulated with 10 μg/ml Anisomycin for 15 min before lysis (+AIM). The indicated markers were assayed by western blotting. (c) REH (left panel) and 697 cells (right panel) were incubated with 20 μM BIRB-796 (BIRB) or SB203580 (SB) alone or in combination with chemotherapeutic drugs for 48 h, as indicated. MTX, 30 nM Methotrexate (REH and 697); VCR, 1 nM (REH) and 2 nM (697) Vincristine; DXM, 100 nM (REH) and 50 nM (697) Dexamethasone; AraC, 50 nM Cytarabine (REH and 697); Dauno, 100 nM Daunorubicine (REH and 697). Standard chemotherapeutics were used at concentrations nearest to the IC₅₀ of the individual drug and cell line. Other concentrations are depicted in Supplementary Figure 3. *P <0.05, **P <0.01, ***P <0.001. C, control; GAPDH, glyceraldehyde 3-phosphate dehydrogenase.