Figure 4

⍺-hemolysin impedes tumor growth and induces tumor necrosis. (A) The volumes of 4T1 tumors before (day 0) and after (day 5) intratumoral injections with 1 μg of HLA (in orange, n = 5) or vehicle control (Con, in black, n = 5). (B) The volumes of EO771 tumors before (day 0) and after (day 4) intratumoral injections with 2 μg of HLA (in red, n = 10) or vehicle control (in gray, n = 5). (C) Representative images of 4T1 tumors that were isolated 2 days after the intratumoral injection of 1 μg of HLA or vehicle control (Con) and subjected to H&E stain (upper panel) and immunohistochemistry (IHC) staining for cleaved caspase-3 (middle panel) and cleaved caspase-1 (lower panel). Scale bars are shown in black at 1000 μm. (D) Quantification of the tumoral area that were stained with the cleaved caspase-3 antibody in different treatment groups based on the IHC staining of (C) (n = 11 or 10). Data are presented as mean ± s.e.m ((A), (B), and (D)). Two-way analysis of variance (ANOVA) with multiple comparisons ((A) and (B)). Unpaired two-tailed Student’s t-test (D). *P < 0.05; **P < 0.01; ns, not significant.