title: Genetically engineered theranostic mesenchymal stem cells for the evaluation of the anticancer efficacy of enzyme/prodrug systems.
abstract: Over the past decade, various enzyme/prodrug systems such as thymidine kinase/ganciclovir (TK/GCV), yeast cytosine deaminase/5-fluorocytosine (yCD/5-FC) and nitroreductase/CB1954 (NTR/CB1954) have been used for stem cell mediated suicide gene therapy of cancer. Yet, no study has been conducted to compare and demonstrate the advantages and disadvantages of using one system over another. Knowing that each enzyme/prodrug system has its own strengths and weaknesses, we utilized mesenchymal stem cells (MSCs) as a medium to perform for the first time a comparative study that illustrated the impact of subtle differences among these systems on the therapeutic outcome. For therapeutic purposes, we first genetically modified MSCs to stably express a panel of four suicide genes including TK (TK007 and TK(SR39) mutants), yeast cytosine deaminase:uracil phosphoribosyltransferase (yCD:UPRT) and nitroreductase (NTR). Then, we evaluated the anticancer efficacies of the genetically engineered MSCs in vitro and in vivo by using SKOV3 cell line which is sensitive to all four enzyme/prodrug systems. In addition, all MSCs were engineered to stably express luciferase gene making them suitable for quantitative imaging and dose-response relationship studies in animals. Considering the limitations imposed by the prodrugs' bystander effects, our findings show that yCD:UPRT/5-FC is the most effective enzyme/prodrug system among the ones tested. Our findings also demonstrate that theranostic MSCs are a reliable medium for the side-by-side evaluation and screening of the enzyme/prodrug systems at the preclinical level. The results of this study could help scientists who utilize cell-based, non-viral or viral vectors for suicide gene therapy of cancer make more informed decisions when choosing enzyme/prodrug systems.
authors.affiliation: Department of Pharmaceutics, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA.
authors.forename: Faranak Salman
authors.initials: FS
authors.lastname: Nouri
authors.affiliation: Department of Pharmaceutics, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA.
authors.forename: Xing
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Pharmaceutics, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA. Electronic address: ahatefi@pharmacy.rutgers.edu.
authors.forename: Arash
authors.initials: A
authors.lastname: Hatefi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D045744:Cell Line, Tumor; D002470:Cell Survival; D043525:Cytosine Deaminase / Q000235:genetics; D005260:Female; D005437:Flucytosine / Q000008:administration & dosage*; D015316:Genetic Therapy; D057809:HEK293 Cells; D006801:Humans; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells; D008819:Mice, Nude; D009369:Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D010430:Pentosyltransferases / Q000235:genetics*; D011355:Prodrugs / Q000008:administration & dosage*; D013937:Thymidine Kinase / Q000235:genetics; D047368:Tumor Burden / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D011355:Prodrugs; D005437:Flucytosine; D010430:Pentosyltransferases; C023269:uracil phosphoribosyltransferase; D013937:Thymidine Kinase; D043525:Cytosine Deaminase
keywords: Cancer gene therapy; Cytosine deaminase; Enzyme prodrug; Mesenchymal stem cells; Suicide genes; Thymidine kinase