| Co-Investigator(Kenkyū-buntansha) |
ISOBE Ken-ichi Nagoya University School of Medicine, Department of Immunology, Associate profes, 医学部, 助教授 (20151441)
TAKESHITA Hiroki Nagoya University School of Medicine, Second Department of Surgery, Research ass, 医学部, 医員
SEKIGUCHI Hiroyuki Nagoya University School of Medicine, Second Department of Surgery, Research ass, 医学部, 医員
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1996: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1995: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
The possibility of using adenoviruses for gene therapy of gastrointestinal cancer was investigated. First, a lacZ gene with an inserted adenovirus (AxlacZ) was used as a reporter gene for in vitro and in vivo infection experiments. Cultured cell strains from esophageal, stomach, and large intestinal cancers were placed in contact with AxlacZ in vitro, and the adenovirus infectivity was examined using X-gal stain. A considerable difference in infectivity was seen between the cell strains, varying from about 20% to nearly 100%. Next, the cell line was implanted subcutaneously in nude mice, AxlacZ was injected directly into the tumor, and several days later the tumor was excised. It was then stained with X-gal, and the adenovirus infection was confirmed. In addition, cellular immunity from the adenovirus was investigated using BALB/c mice and large intestinal cancer cell line colon 26 from them. AxlacZ was first administered into the mouse abdominal cavity, and afterward colon 26 infected
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with AxlacZ was implanted into the mice. Tumor growth was suppressed compared to when no AxlacZ pre-treatment was given, suggesting establishment of cellular immunity.
Next, recombinant adenovirus (Axp53) expressing wild-type p53 was prepared, and used to investigated the antitumoral effect in the esophageal cancer cell line in vitro and in vivo. The cell line was infected with Axp53 in vitro and cell survival was examined in an MTT assay. A variation of about 20% to 90% was seen, depending on the cell line. In the in vivo investigation, the cell line was implanted subcutancously in nude mice, and AxlacZ or Axp53 was injected directly. Suppression of cell proliferation was seen with AxlacZ,but Axp53 proved to be even more effective. In the region of the Axp53 injection p53 protein expression was confirmed by immunostaining. The combination of Axp53 with an anticancer agent was also investigated both in vitro and in vivo, but only an additive effect was obtained.
In light of the foregoing, p53 recombinant adenovirus is seen to be an effective gene therapy for gastrointestinal cancer. Less
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