(Fig. 3A, B). To confirm the synergistic effects of As2O3 with DDP CalcuSyn™ program (Version 2.0, Biosoft, Inc., UK) was explored to make dose-effect curves and to determine the combination indices (CI) (Fig. 4A,B). #Staurosporine in vivo randurls[1|1|,|CHEM1|]# The CI for A549 and H460 were 0.5 and 0.6, respectively which confirmed the synergism of As2O3 with DDP. Figure 1 Dose response curves for effects of As 2 O 3 on A549 and H460 lung cancer cell proliferation. Cells were treated with different concentrations of As2O3 (10-6–10 μM) for 72 hours. Proliferation was analyzed by MTT assay. As2O3 concentrations of 10-2 μM to 10 μM inhibited A549 cell proliferation at 72 hours.

Figure 2 Clonogenic assay of the effects of As 2 O 3 on the proliferation of A549 and H460 cells. In vitro clonogenic assays showed that 10-1 μM to 12.5 μM As2O3 inhibited the proliferation

of A549 and H460 cells. Surviving fraction was calculated as (mean colony counts)/(cells inoculated) × (plating efficiency), where plating efficiency was defined as mean colony counts/cells inoculated for untreated controls. Figure 3 Synergistic effects of As 2 O 3 and DDP in lung cancer cell lines. A. The synergistic effect of As2O3 and DDP in the treatment of A549 cells. MTT assay results showed that 2.5 μM As2O3 and 3 μg/ml DDP exerted synergistic inhibition effects on A549 cells at 48 hours. B. The synergistic effect of As2O3 and DDP in the treatment of H460 cells. MTT assay results showed that 2.5 JAK inhibitor μM As2O3 and 3 μg/ml DDP exerted synergistic inhibition effects on H460 cells at 48 hours. Figure 4 Dose effect curve for A549 (A) and H460 (B) cells. The concentration of DDP was 3 μg/ml and the concentration for As2O3 ranged from 0.1 μM to 12.5 μM. CalcuSyn™ (Version 2.0, Biosoft, Inc., UK) was used for dose-effect curves and to determine the next combination indices (CI). As2O3 did not significantly affect the cell cycles of

A549 and H460 cells A549 cells were treated with 2.5 μM As2O3 and/or 3 μg/ml DDP for 48 hours. FCM cell cycle analysis showed that the treatment of As2O3 and/or DDP did not significantly alter G0/G1 fractions of A549 cells compared with those of the control. The G0/G1 fraction ranged from 57% to 62% for controlled A549 cells and cells treated with As2O3 and/or DDP; the G0/G1 fraction ranged from 37% to 42% for controlled H460 cells and cells treated with As2O3 and/or DDP (Fig. 5). Western blot analysis showed that As2O3 and/or DDP did not affect the expression of cell cycle related protein p21 and cyclin D1 (data not shown). Figure 5 G0/G1 fraction analysis. FCM cell cycle analysis showed that the treatment of As2O3 and/or DDP did not significantly affect G0/G1 fractions of A549 and H460 cells compared with those of the control. The G0/G1 fraction ranged from 57% to 62% for control A549 cells and for A549 cells treated with As2O3 and/or DDP, and from 37% to 42% for control H460 cells and for H460 cells treated with As2O3 and/or DDP.