Fig. 1

smTRAIL induces tumor cell apoptosis and antitumor responses in mouse models. A Murine cancer cell lines were treated with the indicated concentrations of smTRAIL for 16 h, and cell viability was determined by MTT assay. B Tumor growth curves and C survival curves with three concentrations of smTRAIL in different tumor-bearing models (n = 8). BALB/c mice were subcutaneously (s.c.) inoculated with 5 × 10⁴ 4T1 cells or 2 × 10⁵ CT26 cells, whereas C57BL/6 mice were s.c. inoculated with 1 × 10⁵ B16 cells in the right flanks, and smTRAIL was injected intraperitoneally (i.p.) for eight consecutive days. D Detection of caspase-3 in tumor tissues. Mice treated with different doses of smTRAIL were euthanized on day 20. Activation of caspase-3 was detected by immunohistochemistry. Scale bars, 50 μm. E Data indicate the percentage of caspase-3 positive cells in tissue sections, with at least 5 images being analyzed. A two-way ANOVA test was used to compare the tumor growth responses. *P < 0.05; **P < 0.01; ***P < 0.001 and ****P < 0.0001