title: An Inducible Caspase-9 Suicide Gene to Improve the Safety of Therapy Using Human Induced Pluripotent Stem Cells.
abstract: Human induced pluripotent stem cells (hiPSC) hold promise for regenerative therapies, though there are several safety concerns including the risk of oncogenic transformation or unwanted adverse effects associated with hiPSC or their differentiated progeny. Introduction of the inducible caspase-9 (iC9) suicide gene, which is activated by a specific chemical inducer of dimerization (CID), is one of the most appealing safety strategies for cell therapies and is currently being tested in multicenter clinical trials. Here, we show that the iC9 suicide gene with a human EF1α promoter can be introduced into hiPSC by lentiviral transduction. The transduced hiPSC maintain their pluripotency, including their capacity for unlimited self-renewal and the potential to differentiate into three germ layer tissues. Transduced hiPSC are eliminated within 24 hours of exposure to pharmacological levels of CID in vitro, with induction of apoptosis in 94-99% of the cells. Importantly, the iC9 suicide gene can eradicate tumors derived from hiPSC in vivo. In conclusion, we have developed a direct and efficient hiPSC killing system that provides a necessary safety mechanism for therapies using hiPSC. We believe that our iC9 suicide gene will be of value in clinical applications of hiPSC-based therapy.
authors.affiliation: Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital, and Houston Methodist Hospital, Houston, Texas, USA.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Yagyu
authors.affiliation: Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital, and Houston Methodist Hospital, Houston, Texas, USA.
authors.forename: Valentina
authors.initials: V
authors.lastname: Hoyos
authors.affiliation: Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital, and Houston Methodist Hospital, Houston, Texas, USA.|Department of Pediatric Hematology/Oncology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Del Bufalo
authors.affiliation: Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital, and Houston Methodist Hospital, Houston, Texas, USA.
authors.forename: Malcolm K
authors.initials: MK
authors.lastname: Brenner
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D053453:Caspase 9 / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression; D023061:Gene Order; D017930:Genes, Reporter; D041722:Genes, Transgenic, Suicide; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism*; D016086:Lentivirus / Q000235:genetics; D008297:Male; D051379:Mice; D013724:Teratoma / Q000235:genetics / Q000473:pathology / Q000628:therapy; D019076:Transgenes; D023041:Xenograft Model Antitumor Assays
chemical_list: D053453:Caspase 9