Figure 1

SNALP delivers siRNA to normoxic areas within tumor sections. Mice bearing the TetR-ODC-LacZ-derived liver tumors were administrated with SNALP liposomes containing the TetR siRNA on day 1 and day 4 (intravenous (i.v.), 2.5 mg siRNA per kg). In all, 0.2 ml pimonidazole HCl solution (6 mg per ml in saline) was administrated via i.v. injection 1 h before sample harvesting on day 7. Adjacent sequential serial sections of the same tumor were analyzed for β-galactosidase expression (right panel) and tumor hypoxia (left panel). Tumors from five mice were analyzed, and two representative fields were shown here. Equivalent regions in adjacent sections are highlighted using dotted lines. (a) Field 1 at × 5 magnification. (b) Field 2 at × 10 magnification.