title: Annexin V-Directed Enzyme Prodrug Therapy Plus Docetaxel for the Targeted Treatment of Pancreatic Cancer.
abstract: OBJECTIVE
  The bleak prognosis associated with pancreatic cancer (PDAC) drives the need for the development of novel treatment methodologies. Here, we evaluate the applicability of 3 enzyme prodrug therapies for PDAC, which are simultaneously targeted to the tumor, tumor vasculature, and metastases via annexin V. In these therapies, annexin V is fused to an enzyme, creating a fusion protein that converts nontoxic drug precursors, prodrugs, into anticancer compounds while bound to the tumor, therefore mitigating the risk of side effects.
  
  
  METHODS
  The binding strength of fusion proteins to the human PDAC cell lines Panc-1 and Capan-1 was measured via streptavidin-horseradish peroxidase binding to biotinylated fusion proteins. Cytotoxic efficacy was evaluated by treatment with saturating concentrations of fusion protein followed by varying concentrations of the corresponding prodrug plus docetaxel.
  
  
  RESULTS
  All fusion proteins exhibited strong binding to PDAC cells, with dissociation constants between 0.02 and 1.15 nM. Cytotoxic efficacy was determined to be very good for 2 of the systems, both of which achieved complete cell death on at least 1 cell line at physiologically attainable prodrug concentrations.
  
  
  CONCLUSIONS
  Strong binding of fusion proteins to PDAC cells and effective cytotoxicity demonstrate the potential applicability of enzyme prodrug therapy to the treatment of PDAC.
authors.affiliation: From the *Biomedical Engineering Center and the School of Chemical, Biological and Materials Engineering, and †Oncology-Hematology Section, Health Sciences Center, University of Oklahoma, Norman, OK.
authors.forename: Katrin P
authors.initials: KP
authors.lastname: Guillen
authors.forename: Antonietta
authors.initials: A
authors.lastname: Restuccia
authors.forename: Carla
authors.initials: C
authors.lastname: Kurkjian
authors.forename: Roger G
authors.initials: RG
authors.lastname: Harrison
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D000230:Adenocarcinoma / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D017304:Annexin A5 / Q000378:metabolism*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D013437:Carbon-Sulfur Lyases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D043525:Cytosine Deaminase / Q000378:metabolism; D000077143:Docetaxel; D004305:Dose-Response Relationship, Drug; D004798:Enzymes / Q000378:metabolism*; D005437:Flucytosine / Q000378:metabolism / Q000494:pharmacology; D005472:Fluorouracil / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D000432:Methanol / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D058990:Molecular Targeted Therapy; D016566:Organoselenium Compounds / Q000378:metabolism / Q000494:pharmacology; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D011355:Prodrugs / Q000378:metabolism / Q000494:pharmacology*; D011683:Purine-Nucleoside Phosphorylase / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012645:Selenomethionine / Q000378:metabolism / Q000494:pharmacology; D043823:Taxoids / Q000494:pharmacology*; D050257:Tubulin Modulators / Q000494:pharmacology*; D014740:Vidarabine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology
chemical_list: D017304:Annexin A5; D004798:Enzymes; D016566:Organoselenium Compounds; D011355:Prodrugs; D011993:Recombinant Fusion Proteins; D043823:Taxoids; D050257:Tubulin Modulators; D000077143:Docetaxel; C038208:2-fluoroadenine; C019003:methaneselenol; D012645:Selenomethionine; D005437:Flucytosine; D011683:Purine-Nucleoside Phosphorylase; D043525:Cytosine Deaminase; D013437:Carbon-Sulfur Lyases; C021558:L-methionine gamma-lyase; D014740:Vidarabine; D000225:Adenine; C024352:fludarabine; D005472:Fluorouracil; D000432:Methanol