Figure 4. Intercomplementing toxin induces massive tumor necrosis in xenografted human Hep2 tumors, but does not affect proliferation, vascularization or apoptosis in viable tumor areas.

Necrosis (A), proliferation (B), tumor vascularization (C), and apoptosis (D) of Hep2 xenografts five days after initiation of systemic treatment with either PBS (blue bars and left panels) or intercomplementing toxin (red bars and right panels). A, hematoxylin and eosin staining. B, Ki67 staining. C, PECAM-1 staining. D, TUNEL staining. N in A and B indicates necrotic area. Tumor margins in A–C are indicated with dotted lines. Arrows in D highlight examples of TUNEL positive cells. Columns, mean; bars, standard error of the mean, *, P<0.05. In all cases, representative images are shown. Scale Bars; 100 µM.