Figure 7.

Effect of AS602868 combined with CPT-11 on TNFα intratumoural concentration and induction of TNFα apoptosis potential in HT-29 cells by AS602868. (A) Histological examination of HT-29 tumour xenografts after 6 (control and AS602868 groups) or 10 weeks of treatment (CPT-11 and CPT-11+AS60286 groups). Tumour sections were stained with an anti-TNFα antibody. Magnification: × 320. (B) HT-29 cells were incubated for 5 days with AS602868, TNFα or both molecules simultaneously or SN-38, TNFα or both molecules or AS602868, TNFα and SN-38 together. Cytotoxicity was evaluated using the MTT assay. Data are expressed as means±s.d. of quadruplicates of one representative experiment from 3. ^* indicates detection of the synergistic effects of AS602868±TNFα±SN-38 on cell viability by using the non-constant ratio isobologram method. (C) Cleavage of Parp-α and pro-caspase 3 was demonstrated by western blotting on lysates of HT-29 cells incubated for 72 h with indicated concentrations of AS602868±SN-38. HSP60 was used as loading control. (D) NF-κB activation was visualized by EMSA. HT-29 cells were treated with indicated concentrations of AS602868, 30 min before stimulation with TNFα (10 ng ml⁻¹) for 1 h. These results correspond to one representative experiment from 3.