Figure 5. Zt/f2 treatment inhibits Raji cell xenograft growth. (A) Zt/f2 treatment significantly suppresses the growth of Raji cell xenografts in athymic nude mice. Tumor-bearing mice were randomized into different groups (three mice per group). Animals were treated with Zt/f2, PBS or control mouse IgG at the doses and schedule defined in the Materials and Methods section. For each treatment group, the tumor volume was measured weekly. Tumor xenograft tissues were harvested after 7 weeks. (B) The tumor growth index in control mice was set to 1.00 and used to make comparisons among groups. (C, D) Immunohistochemical detection of TUNEL-positive and RON⁺ cells in tumor xenograft tissues. The percentage of positively stained cells in the tissues of each group is shown. TUNEL-positive and RON⁺ cells were counted in four or five different fields, the data are summarized as the mean of percentage positive cells in three xenograft samples. The proportion of apoptotic cells was significantly increased and there was a clear downregulation of RON in Zt/f2-treated samples. *, p < 0.05 vs. PBS control group.