| Project/Area Number |
09557121
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 展開研究 |
|---|
| Research Field |
Cerebral neurosurgery
|
|---|
| Research Institution | Keio University |
|---|
Principal Investigator |
YAZAKI Takahito Keio Univ Sch of Med, Dept of Physiology, Assistant professor, 医学部, 専任講師 (80200484)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HISHI Michio Keio Univ Sch of Med, Dept of Physiology, Instructor, 医学部, 助手 (00265844)
植村 慶一 慶應義塾大学, 医学部, 教授 (90049792)
KAWASE Takeshi Keio Univ Sch of Med, Dept of Neurosurgery, Professor, 医学部, 教授 (40095592)
SUGAWA Makoto Chugai Pharmaceutical Co., Ltd., Pharmaceutical Tech. Lab., Senior scientist, 研究主査
TODA Masahiro Keio Univ Sch of Med, Inst of Advanced Med, Instructor, 医学部, 助手 (20217508)
寺尾 聡 慶應義塾大学, 医学部, 助手 (70276278)
|
|---|
| Project Period (FY) |
1997 – 1999
|
| Project Status |
Completed (Fiscal Year 1999)
|
| Budget Amount *help |
¥11,400,000 (Direct Cost: ¥11,400,000)
Fiscal Year 1999: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1998: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1997: ¥6,600,000 (Direct Cost: ¥6,600,000)
|
|---|
| Keywords | Brain tumors / Herpes simplex virus / unvasion / cytotoxic T cells / gene therapy |
|---|
| Research Abstract |
We have investigated a combined gene therapy to express several functional genes from a suitable vector system. The strategy behind the use of replication-competent, cytotoxic viral vector is that after infection of a tumor cell the viral vector replicates and kills the infected cell, producing multiple infectious progeny that then infects additional tumor cells and this replication cycle is repeated until the viral infection reaches normal tissue. At first we have generated multiple mutant HSV-G207 which has deletions of both copies of the ICP34.5 gene and a lacZ insertion inactivating the ICP6 gene. In vitro, G207 was able to replicate in and destroyed a large number of tumor tell lines. In athymic mice harboring subcutaneous or intracranial human malignant brain tumor cells, G207 infection caused significantly decreased tumor growth and/or prolonged survival. However, for actively invasive or rapidly proliferating malignant tumors, virus replication was not enough to kill most of tumor cells. Tissue inhibitor of metalloptoreinases type 2 (TIMP2) is specific inhibitor of MMP2 and 9, and should decrease invasive activity of malignant tumor cells. Interferon gamma may induce cytotoxic T cells against tumors. To strengthen therapeutic strategy of replication-competent HSV therapy, we have generated defective HSV vector expressing TIMP2 or IFN gamma by insertion of those cDNA into HSV-amplicon plasmid using HSV-G207 as a helper virus. Theoretically these viruses should replicate in tumor cells and synchronously secrete TIMP2 or IFN gamma into surrounding tissue. In fact, after infection of this virus, especially a combination of two vectors, we observed that glioma cells decreased their activity of mitosis and invasion both in vitro and in vivo. These newly developed HSV vectors increased tumor killing ability comparing with G207. This type of combined gene therapy strategy using single vector system may be an appropriate approach for treating malignant tumors.
|
