2009 Fiscal Year Final Research Report

Liposomal Interleukin-15 Gene Therapy in an Orthotopic Bladder Cancer Model and Acquirement of Immunologic Memory

Research Project

Project/Area Number	20791121
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Urology
Research Institution	Keio University
Principal Investigator	MATSUMOTO Kazuhiro Keio University, 医学部, 助教 (80366153)
Project Period (FY)	2008 – 2009
Keywords	インターロイキン-15 / 遺伝子治療 / 免疫治療 / 筋層非浸潤性膀胱癌
Research Abstract	In proportion to the liposomal transfection efficiency in vitro, the IL-15 concentrations in the culture supernatant were dose-dependent after the IL-15 gene plasmid transfection. Our results in vivo showed that using liposome-mediated in situ gene transfer via simple intravesical instillation, intravesical IL-15 plasmid transfection in situ exhibits significant tumor suppression in an orthotopic bladder cancer model, and that CD8^+ T-cells seemed to be associated with its anti-tumor effect. In mice that survived the intravesical IL-15 gene therapy, rechallenged MBT-2 cells were suppressed and they had the potential to acquire immunologic memory. In conclusion, the present data indicate that IL-15 gene therapy may be a promising new adjuvant therapy for non-muscle invasive bladder cancer and a useful substitute for BCG treatment.