| abstract |
Novel pro-drugs and methods for their use to alter the growth and biological characteristics of living cells, tissues, or whole organisms are described. The methods allow for selective activation of the pro-drugs at or near transformant host cells expressing a gene for an enzyme that activates the pro-drugs. Pro-drugs according to a preferred embodiment of the invention are conjugates of a bioactive compound and a chemical group that is capable of being cleaved from the bioactive compound by action of an enzyme. Methods according to this invention include, (a) introducing into targeted cells a gene encoding an enzyme and (b) administering a pro-drug, wherein the enzyme releases the pro-drug from conjugation. In a preferred embodiment of the invention, the gene encoding the enzyme is a marker gene. |