Figure 2
o-OPN induces necrosis but not growth arrest or apoptosis. (A and B) H&E-stained sections from representative tumours showing areas of necrosis (indicated by dashed lines). (A) control tumour; (B) tumour from an o-OPN treated mouse collected on day 21. Bar=100 μm. (C) Quantification of necrotic areas in control and o-OPN tumours: OPN was administered at 0.3 mg ml−1, and tumours were collected on day 17 (water and OPN d17, n=10 and 5, respectively) or on day 21 (OPN d21, n=8). Necrotic areas were assessed in H&E-stained sections, measured and expressed as a percentage of the total tumour area in the section. (D) Proliferation was assessed by Ki67 staining, and percentage of positive cells was determined by counting; groups as in panel (C). (E) Caspase 3/7 activity was determined biochemically in lysates from water- and o-OPN-treated mice; groups as in panel (C). *P<0.01 vs water group (one-way ANOVA).
