Fig. 6

Treatment effects of IFN-β and gemcitabine in a subcutaneous heterotopic human pancreatic cancer model. a Experimental design for in vivo experiments. BxPC-3 human pancreatic cancer cells (1 × 10⁶ /100 μl PBS) were subcutaneously injected in nude mice. Seven day later, groups of mice received five times a week, on consecutive days, an i.p. injection of IFN-β (1.5 × 10⁵ IU), two times a week (at day 2 and 4) an i.p. injection of gemcitabine (40 mg/kg), or the combination of IFN-β plus gemcitabine. Mice in the control group received five times a week, on consecutive days, an intraperitoneal (i.p.) injection of 100 μl of 0.9% NaCL. b Time course of change in tumor volume (left). After 4 weeks of treatment, mice were sacrificed and tumor volume was measured (right). c Photomicrographs of representative tissue slides of immunohistochemical staining for Ki-67 or cleaved caspase-3, d Immunohistochemical analysis of Ki-67 (left) and cleaved caspase-3 (right) expression, representing the proportion of proliferating cells and the proportion of apoptotic cells respectively. Values represent mean ± SEM of at least three different areas within the tumor and are shown as a percentage of control. **p < 0.01 and ***p < 0.001 versus control