Transcellular Invasion of MM1 Rat Ascites Hepatoma Cells Requires Matrix Metalloproteinases Derived from Host Mesothelium

抄録

Degradation of the extracellular matrix by proteases secreted by invading tumor cells is thought to be essential for metastasis. Using an in vitro transcellular migration assay model, we examined the requirement of matrix metalloproteinases (MMP) in the invasion of MM1 rat hepatoma cells through normal mesothelial cell monolayers. Here we show that MM1 cells transmigrate using MMPs not expressed in the tumor cells but secreted by host mesothelial cells. Additionally, the amount of MMP secreted by mesothelial cells was increased by co-culture with hepatoma cells. Our results point to the role of normal host cells in the tumor microenvironment as a source of invasion factors necessary for the metastatic process.