An animal model for colon cancer metastasis: establishment and characterization of murine cell lines with enhanced liver-metastasizing ability.

A detailed understanding of the pathogenesis of colon cancer metastasis has been hindered by the lack of appropriate animal models which accurately reflect events in this complex process. An animal model for colon cancer metastasis is described in which spontaneously metastasizing colonic tumors are formed after injection of murine colon cancer cells into the cecal wall of BALB/c mice. Using this model, tumor cells with different liver-metastasizing potential were selected and shown to possess several properties known to be associated with other metastatic cell lines. The ability of tumor cells to invade a reconstituted basement membrane and to secrete type IV collagenase was directly proportional to their metastatic ability. In addition, liver-metastasizing cells preferentially migrated toward liver extracts in a Boyden chamber assay, as compared to extracts of brain or lung, and adhered rapidly to highly purified hepatic sinusoidal endothelial cells versus hepatic parenchymal cells in vitro. This model may thus be useful for studying many aspects of the pathogenesis of colon cancer metastasis.