%0 Journal Article %T A Suicide Gene Therapy Combining the Improvement of Cyclophosphamide Tumor Cytotoxicity and the Development of an Anti-Tumor Immune Response %+ Unité de Technologies Chimiques et Biologiques pour la Santé (UTCBS - UM 4 (UMR 8258 / U1022)) %A Touati, Walid %A Tran, Thi %A Seguin, Johanne %A Diry, Monique %A Flinois, Jean-Pierre %A Baillou, Claude %A Lescaille, Geraldine %A Andre, Francois %A Tartour, Eric %A Lemoine, Francois M. %A Beaune, Philippe %A de Waziers, Isabelle %< avec comité de lecture %@ 1566-5232 %J Current Gene Therapy %I Bentham Science Publishers %V 14 %N 3 %P 236-246 %8 2014 %D 2014 %R 10.2174/1566523214666140424152734 %K REGULATORY T-CELLS %K ENZYME EXPRESSION %K LENTIVIRAL VECTOR %K ESCHERICHIA-COLI %K LUNG-CANCER %K HUMAN LIVER %K LINE PANEL %K B-SUBUNIT %K IN-VIVO %K ANTIGEN %Z Life Sciences [q-bio]/BiotechnologyJournal articles %X Gene-directed enzyme prodrug therapy (GDEPT) consists in targeted delivery to tumor cells of a suicide gene responsible for in situ conversion of a prodrug into cytotoxic metabolites. One of the major limitations of this strategy in clinical application was the poor prodrug activation capacity of suicide gene. We built a highly efficient suicide gene capable of bioactivating the prodrug cyclophosphamide (CPA) by fusing a CYP2B6 triple mutant with NADPH cytochrome P450 reductase (CYP2B6TM-RED). Expression of this fusion gene via a recombinant lentivirus (LV) vector converted resistant human (A549) and murine (TC1) pulmonary cell lines into CPA-susceptible cell lines. We tested the efficiency of our GDEPT strategy in C57Bl/6 immunocompetent mice, using TC1 cells expressing the HPV-16 E6/E7 oncoproteins. In mice bearing tumors composed only of TC1-CYP2B6TM-RED cells, four CPA injections (140 mg/Kg once a week) completely eradicated the tumors for more than two months. Tumors having only 25% of TC1-CYP2B6TM-RED cells were also completely eradicated by five CPA injections, demonstrating a major in vivo bystander effect. Moreover, surviving mice were rechallenged with parental TC1 cells. The tumors regressed spontaneously 7 days after cell inoculation or grew more slowly than in control naive mice due to a strong immune response mediated by anti-E7CD8(+)T cells. These data suggest that combining the CYPB6TM-RED gene with CPA may hold promise as a highly effective treatment for solid tumors in humans. %G English %L hal-03291078 %U https://cnrs.hal.science/hal-03291078 %~ UNIV-PARIS5 %~ ENSCP %~ CNRS %~ ENSC-PARIS %~ PARISTECH %~ INC-CNRS %~ PSL %~ UNIV-PARIS %~ UP-SANTE %~ ENSCP-PSL %~ UTCBS %~ TEST2-HALCNRS