Cadherin/catenin complex: A target for antiinvasive therapy?

Invasion is a major challenge for cancer therapy. Invasion or noninvasion results from the cross talk between cancer cells and host cells, building molecular invasion-promoter and invasion-suppressor complexes. The E-cadherin/catenin invasion-suppressor complex is attractive as a target for a putative antiinvasive therapy because of its multifactorial regulation at multiple levels and sometimes in a reversible way. Mutations in the E-cadherin gene combined with loss of the wild type allele causes irreversible downregulation in some human cancers. Posttranslational and reversible downregulation may occur by tyrosine phosphorylation of β-catenin. Phosphorylation is implicated also in transmembrane receptor signal transduction through the E-cadherin/catenin complex. Homophilic interaction with E-cadherin on another cell through a dimeric adhesion zipper, involving the HAV sequence of the first extracellular domains, is the major extracellular link of the E-cadherin/catenin complex. Intracellularly, the list of proteins that bind to or signal through the complex or one or more of its elements is growing. In vitro, insulin-like growth factor-I, and tamoxifen may upregulate the functions of the E-cadherin/catenin complex and inhibit invasion, demonstrating that this complex may serve as a target for antiinvasive therapy. © 1996 Wiley-Liss, Inc.