(A) Schematic diagram illustrating the study workflow. Mice were injected with UM-UC-3 cells (5×105/tumor) together with Matrigel. Two weeks after inoculation, mice were randomly divided into three groups (n = 6 per group; control (no treatment), negative control siRNA, and human KLγ siRNA). Then, mice were treated once a week for 4 weeks. Three days after the last treatment, mice were euthanized and xenografts were harvested. (B) The treatment with KLγ siRNA suppressed the expression levels of KLγ mRNA in UM-UC-3, as measured by RT-PCR analysis. (C) The resected xenografts from treatment group were photographed. (D) Intratumoral treatment with KLγ siRNA caused significant resected xenograft weight loss compared to both the control group and the group of mice treated with negative control siRNA (Mann–Whitney U test; * = P< 0.05). (E) Tumor growth rate during treatment was significantly lower in mice treated with KLγ siRNA compared to both the control group and the group of mice treated with negative control siRNA (Mann–Whitney U test; * = P< 0.05).