However, this cleavage did not take place in Ad5-TRAIL-MRE-1-133-218-treated normal bladder mucosal cells (Figure 3b). Similarly, cleavages of caspase-3 and PARP proteins were also observed in the same patterns as caspase-8, suggesting extrinsic apoptotic pathway was selectively activated in bladder cancer cells when Ad5-TRAIL-MRE-1-133-218 was used (Figure 3b). Ad-TRAIL-MRE-1-133-218 decreased the survival of bladder cancer cells rather than normal bladder mucosal cells We next investigated the viability of bladder cancer cells and BMCs with MTT assay, when Ad-EGFP, Ad-TRAIL and Ad-TRAIL-MRE-1-133-218 were added to the indicated cell cultures. The data revealed that
Ad-TRAIL-MRE-1-133-218 had a comparative tumor-suppressing capacity on T24 and RT-4 bladder cancer cells as well as primary bladder carcinoma cells with Ad-TRAIL (Figure 3c). Proteasome inhibitor However, Ad-TRAIL had cytotoxicity to both cancerous and normal bladder cells. In contrast, administration of Ad-TRAIL-MRE-1-133-218 did not affect the survival of BMCs. Collectively, we proved that Ad-TRAIL-MRE-1-133-218 inhibited the viability of bladder cancer cells without significant cytotoxicity to normal cells. Ad-TRAIL-MRE-1-133-218 suppressed the growth of bladder cancer xenograft in mouse models
Next, we intended to further investigate the suppressive action of Ad-TRAIL-MRE-1-133-218 on bladder cancer xenograft using mouse models. T24 and RT-4 bladder cancer cells were used to establish the tumor xenografts. We periodically recorded the growth of these bladder cancer xenografts when Ad-EGFP, buy GSK458 Ad-TRAIL and Ad-TRAIL-MRE-1-133-218 were administered. The data demonstrated that Ad-TRAIL and Ad-TRAIL-MRE-1-133-218 had a similar growth-inhibiting effect on both T24 and RT-4 bladder cancers (Figure 4a and b). The animal experiments consistently demonstrated Astemizole that MREs-regulated adenovirus-mediated TRAIL expression had a strong tumor-suppressing effect on bladder cancer. Figure 4 Ad-TRAIL-MRE-1-133-218 suppressed the growth of bladder xenograft in mouse models. (a) T24 bladder cancer xenograft was established by subcutaneously
injecting 2×106 cells into left flanks of female BALB/c nude mice. 1×109 pfu of different adenoviruses were treated and the tumor volumes were periodically measured. Means ± SEM of tumor sizes were shown. The arrows indicated time-points of adenovirus injection. (b) RT-4 xenograft was established by subcutaneously injecting 1.5×106 cell into right flanks of female BALB/c nude mice. 1×109 pfu of different adenoviruses were treated and the tumor volumes were periodically measured. Means ± SEM of tumor sizes were shown. The arrows indicated time-points of adenovirus injection. (c) BALB/c nude mice (n=5) were intravenously injected with 1×109 pfu of different adenoviruses every other days for five times. On day 11, their blood was harvested for the measurement of ALT levels. Means ± SEM of ALT serum levels were shown.