[Cancer gene therapy with plasmid expressing anti-HER2/neu-toxin].

The HER2/neu receptor is over-expressed on the surface of many types of cancer cells, and is widely used for tar- geted delivery of anticancer drugs. We have created geneti- cally engineered construct expressing the PE40 fragment of Pseudomonas toxin bound with the DARPin molecule which recognizes the HER2/neu receptor with high specificity. The construct destroyed transfected tumor cells in vitro. Intra-tumor injections of the construct complexed with polyethyleneimine led to growth retardation of D2F2/E2 tumors in mice. These results suggest a possibility of using this approach to develop new anticancer drugs.