A plasmid DNA encoding the A chain of the diphtheria toxin (DT-A) driven by the transcriptional regulatory sequences of human H19, with potential antineoplastic activity. Because the expression of DT-A is under the control of H19 promotor elements, DT-A is selectively expressed in tumor cells capable of turning on H-19. DT-A catalyzes ADP-ribosylation of translation elongation factor 2 (EF-2), resulting in the inhibition of protein synthesis and apoptosis. In addition, DT-A protein released from lysed cells cannot enter and kill neighboring cells because of the absence of the DT-B chain, further enhancing the selective cytotoxicity of this agent. Human H19 is a paternally-imprinted, oncofetal gene encoding an RNA product; it acts as a "riboregulator" in gene expression and is found at substantial levels in different human tumor cell types while its expression in normal adult tissue is limited. Check for active clinical trials using this agent. (NCI Thesaurus)