Imaging beyond the diagnosis: image-guided enzyme/prodrug cancer therapy.
The ideal therapy would target cancer cells while sparing normal tissue. However, in most conventional chemotherapies normal cells are damaged together with cancer cells resulting in the unfortunate side effects. The principle underlying enzyme/prodrug therapy is that a prodrug-activating enzyme is delivered or expressed in tumor tissue following which a non-toxic prodrug is administered systemically. Non-invasive imaging modalities can fill an important niche in guiding prodrug administration when the enzyme concentration is detected to be high in the tumor tissue but low in the normal tissue. Therefore, high therapeutic efficacy with minimized toxic effect can be anticipated. This review introduces the latest developments of molecular imaging in enzyme/prodrug cancer therapies. We focus on the application of imaging modalities including magnetic resonance imaging, position emission tomography and optical imaging in monitoring the enzyme delivery/expression, guiding the prodrug administration and evaluating the real-time therapeutic response in vivo.
School of Pharmacy, Fudan University, Shanghai, China.
Xinyi
X
Tong
Xishan
X
Chen
Cong
C
Li
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D043525:Cytosine Deaminase / Q000627:therapeutic use; D057487:Enzyme Therapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D058990:Molecular Targeted Therapy; D009369:Neoplasms / Q000188:drug therapy*; D049268:Positron-Emission Tomography; D011355:Prodrugs / Q000008:administration & dosage / Q000627:therapeutic use*; D013937:Thymidine Kinase / Q000627:therapeutic use
D000970:Antineoplastic Agents; D011355:Prodrugs; D013937:Thymidine Kinase; D043525:Cytosine Deaminase