Anti-cancer activity of targeted pro-apoptotic peptides

We have designed short peptides composed of two functional domains, one a t umor blood vessel 'homing' motif and the other a programmed cell death-indu cing sequence, and synthesized them by simple peptide chemistry. The 'homin g' domain was designed to guide the peptide to targeted cells and allow its internalization. The pro-apoptotic domain was designed to be nontoxic outs ide cells, but toxic when internalized into targeted cells by the disruptio n of mitochondrial membranes. Although our prototypes contain only 21 and 2 6 residues, they were selectively toxic to angiogenic endothelial cells and showed anti-cancer activity in mice. This approach may yield new therapeut ic agents.