Fig. 3

Knockdown of ITGAV in PaCa 5061 led to an effective reduction of intraperitoneal carcinomatosis after 62 d compared with control PaCa 5061 in E−/P-selectin deficient mice: Only 1/15 animals of the PaCa 5061 ITGAV KD group in wild-type mice showed carcinomatosis formation vs. 11/12 mice with carcinomatoses in the control group (P <  0.0001, a). ITGAV knockdown also reduced tumor growth at the injection site (P <  0.0001, B). 7/15 (ITGAV KD cells in E−/P-selectin k.o. mice) displayed tumors at the injection site vs. 11/12 in the control group (control PaCa 5061 in E−/P-selectin deficient mice). Combination of ITGAV KD and selectin knockout led to further reduction of injection site tumors (P = 0.012; only 2/14 animals with tumors, b). After 77 days, this synergistic effect of ITGAV and E−/P-selectins could also be demonstrated for intraperitoneal carcinomatosis formation (P = 0.017, C; 8/13 mice with tumor take with all eight displaying carcinomatosis with ITGAV KD in wild-type mice vs. 6/14 mice with tumor take and 3 of them displaying carcinomatosis with ITGAV KD in E−/P-selectin deficient animals). Using western blot, the C-terminal deletion of SMAD 4 in BxPC3 cells was confirmed (d). Wild-type mice inoculated subcutaneously with PaCa 5061 ITGAV KD cells showed significantly prolonged survival (tumor take rate 7/10) compared with control cells in wild-type animals (take rate 9/10; P = 0.002, e). Similar results were found for BxPC3 (100% take rate, both groups; P <  0.001, 2H). The number of human cells in the animals’ lungs was significantly reduced in mice injected with PaCa 5061 (P = 0.045, f) and BxPC3 ITGAV KD cells (P = 0.045, I). There was no significant difference for the PaCa5061 (g) or BxPC3 tumor cells circulating in the animals’ blood (j)