The present invention provides a DNA composition comprising a DNA minigene construct that encodes for a polypeptide comprising a plurality of immunogenic fragments of a cysteine endopeptidase that is expressed in tumor-associated cells. The immunogenic fragments are joined together serially by a linker peptide between each successive fragment in the polypeptide. The polypeptide is capable of eliciting an immune response against the tumor-associated cells, is expressible in immune cells, and is incorporated in a pharmaceutically acceptable carrier.