Figure 1
Cutting off tumor blood supply by disconnecting the vasculature between tumor and host using a physical barrier. (A) The schematic shows the experimental procedure. To establish the primary tumor, 2.5 × 106 4T1 cells were injected into a Balb/c mouse (B). When the tumor reached a diameter of approximately 5 mm, it was surgically removed (C) and wrapped with a hydrophilic polycarbonate membrane with 3.0 μm micro-pores (upper panel: electron microscopy image of the surface of the membrane) (D). The membrane-wrapped tumor mass (E) was then implanted into another healthy recipient mouse (F). (G,H) Three weeks after tumor implantation, FITC-conjugated dextran (2000 kD, green) was injected into the mice through the left ventricle and allowed to circulate for 10 min. The 3.0 μm (G) or 8.0 μm (H) membrane-wrapped tumors were then removed completely, including the adjacent tissues, and stained with CD31 (red) to visualize the entire vasculature. As shown in the right panels, the tissues in the host side were well perfused, but green/red co-localization was not observed on the tumor side of the barrier. (I) Under this condition, the tumor and host vasculature was completely disconnected by the physical barrier; on the other hand, the molecules and fluids can cross the border between the host and tumor through the micro-pores.
