An Overview on Enzyme Prodrug Therapy for Cancer.

Cancer is the dangerous disease which caused millions of deaths in worldwide. Enzyme prodrug therapy uses enzymes artificially introduced into the body to convert pro-drugs which have poor biological activity to the active form in the desired location within the body. The use of enzyme pro-drug therapy has gained attention as it has the ability to improve the efficacy and safety of cancer treatment. Chemotherapy for cancer patients has limited success including some drawbacks like systemic toxicity, insufficient drug concentration in tumors. To overcome these drawbacks and improve the cancer treatment the enzyme pro-drug therapy is selected. Enzyme prodrug therapy uses enzymes artificially introduced into the body to convert pro-drugs which have poor biological activity to the active form in the desired location within the body. The selective activation of pro-drugs in tumor tissues by exogenous enzymes for cancer therapy was accomplished by several ways including gene-directed enzyme pro-drug therapy(GDEPT), virus-directed enzyme pro-drug therapy(VDEPT), antibody-directed enzyme pro-drug therapy(ADEPT). Most of these therapies are based on antibody dependent cellular cyto-toxicity, targeted delivery of cytotoxic drugs/tumor site specific activation of prodrugs. This review aims at providing an overview regarding four major systems of GDEPT, ADEPT, VDEPT. Later this review focuses on the bystander effect and combination therapy associated with gene therapy. [ABSTRACT FROM AUTHOR]