Expression of the invasion factor laminin gamma 2 in colorectal carcinomasis regulated by beta-catenin

The migration-inducing gamma2 chain of laminin-5, one of the best known inv asion markers, is strongly overexpressed in disseminating and infiltrating tumor cells at the invasive front of colorectal carcinomas. The same tumor cells show nuclear accumulation of the oncoprotein beta -catenin, which tog ether with T-cell factor-DNA-binding proteins, functions as transcriptional activator of genes involved in tumor progression. Here we show that beta - catenin activates the human laminin-5 gamma2 gene through two T-cell factor -binding elements in a synergistic manner together with hepatocyte growth f actor and conclude that laminin-5 gamma2 is another important target gene o f nuclear beta -catenin during tumor progression.