Methods and compositions for killing replicating or non-replicating, targete d mammalian cells and bystander cells, comprising: (a) transfecting or transducing mammalian cells with a nucleic acid encoding a purine analog nucleoside cleavage enzyme, or providing the targeted cells directly with the enzyme; and (b) contacting the targeted cel ls with a purine analog nucleoside substrate for the enzyme to produce a toxic purine base analog thereby killing the targeted cells and bystander cells. In the present method of killing cells, the enzyme can be an E. coli purine analog nucleoside phosphorylase.
PURINE NUCLEOSIDE PHOSPHORYLASE GENE THERAPY FOR HUMAN MALIGNANCY