Structural and functional aspects of the liver and liver sinusoidal cells in relation to colon carcinoma metastasis

Figure 3 Schematic overview of the early metastatic events occurring along the liver sinusoid in which the LSECs and CC531s colon carcinoma cells (T) play a central role. Fas expressing LSECs (I) undergo apoptosis by FasL expressing CC531s (I and II). By doing so, the colon cancer cells provide themselves a gateway towards the liver parenchyma, as the LSECs retract and gaps are induced in the liver sinusoidal lining (III). Subsequently, the CC531s cells have free access to the hepatocytes, which expresses Fas (III). By this means, CC531s are able to invade in the liver parenchyma. LSECs express FasL and CC531s express Fas (IV). When IFN-γ is present in the sinusoid, Fas becomes active. NO produced by the LSECs induces apoptosis in CC531s cells only when IFN-γ is present (V). As a result the IFN-γ-activated pathway supports the immune system by killing tumor cells. Note: Parenchymal cell (PC). This figure is a compilation of the data reported in Refs. [93,94,96,97].