Fig. 4.

TIC10 induces TRAIL in tumor and normal cells. (A) H&E and IHC analysis of HCT116 p53^−/− xenograft tumors at 2 and 7 days after a single dose of TIC10 on day 0 [100 mg/kg, in-traperitoneally (ip)]. (B) H&E and IHC analysis for TRAIL at the border between tumor and stromal fibroblasts from HCT116 p53^−/− xenograft tumors after treatment with TIC10 (100 mg/kg, ip) or vehicle on day 2 after treatment. The yellow dashed lines indicate stromal fibroblasts, and the black dashed lines indicate the tumor. (C) qRT-PCR analysis of TRAIL transcript in HCT116 p53^−/− xenograft tumors in athymic nude mice after a single dose of DMSO or TIC10 [25 mg/kg, intravenously (iv)] (n = 4). (D) Histological and TRAIL IHC analysis of normal tissue in athymic nude mice after TIC10 administration on day 0 (100 mg/kg, iv). (E) Coculture of HCT116 p53^−/− and HFF cells labeled as red and green, respectively. TIC10 (10 μM)– or DMSO-treated wells are shown immediately before treatment or 3 days after treatment. The bottom two panels were taken at the 3-day endpoint after being counterstained with Hoechst. (F) Surface TRAIL analysis of HFF cells after TIC10 treatment (0, 2.5, 5, or 10 μM from left to right) (72 hours, n = 3). Surface TRAIL is shown relative to cells that were not treated with TIC10. (G) Percentage of sub-G₁ DNA in a coculture of HCT116 p53^−/− cells and pretreated HFFs (24 hours, n = 3). HFF pretreatment consisted of a 72-hour incubation with TIC10 (10 μM) or DMSO. Coculture was in the presence or absence of the TRAIL-blocking antibody RIK-2. Scale bars, 100 μm. Error bars indicate SD of replicates. *P < 0.05, compared to control unless otherwise indicated.