Fig. 9

Selectivity of hsTRAIL-induced death to cancer cells. HCT116 cells and human cardiac fibroblasts were incubated for 48 h with increasing concentration of hsTRAIL present in supernatant from broth culture of L. lactis (hsTRAIL+). As controls in experimental setup were used: corresponding volumes of supernatants from broth culture of L. lactis (hsTRAIL−)—negative control; corresponding concentrations of recombinant human TRAIL (Peprotech)—positive control. Viability of cancer cells and non-malignant, cardiac fibroblasts was assessed by MTS assay. Results are presented as % of viability of cells incubated in standard culture medium only. Secreted hsTRAIL remained non-cytotoxic to fibroblasts (Fig. 9a), while decreased viability of cancer cells in a dose-dependent manner (Fig. 9b). Table below—concentration of hsTRAIL [ng/ml] in specified volume of supernatant. The bars indicate the mean value ± SD of three independent experiments, each performed in triplicates. Statistical significance was calculated using two-way ANOVA with Tukey’s multiple comparison post-test. *p < 0.05, **p < 0.01, ***p < 0.001