Development of a Novel Erizyme/Prodrug Strategy for Gene Therapy of Breast Cancer

摘要

Treatment of advanced breast cancer with standard chemotherapy is often hampered by both local an systemic toxicities. We, therefore, propose to develop an enzyme / prodrug strategy for cancer gene therapy based upon methotrexate prodrugs and the enzyme carboxypeptidase A. To that end we have developed and characterized in vitro mutant forms of carboxypeptidase A which are activated in a trypsin independent manner. Enzymatic analysis of this mutant revealed that it had identical kinetic parameters and substrate specificity as the wild-type enzyme. In addition, expression of either a soluble or cell- surface form of this mutant resulted in potent sensitization of cells in culture to methotrexate-alpha-peptide prodrugs.