| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2001: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
The aim of this study was to investigate the tumor suppressive effect of CEACAM1 (BGPa), a member of the CEA gene family, using a retrovector that expresses the chimeric envelopeprotein containing anti-CEA scFv for targeting to CAE-expressing tumor cells. The results currently obtained are as follows :
1. cDNA for CEACAM1 was prepared from leukocyte mRNA and ligated into the retrovector expressing anti-CEA scFv (GPEscFv-env). Spent culture medium of the resultant clone PLNC-BGPa was used for infection of GPEscFv-env. After many trials using different methods, a few clones were obtained that seemed to produce the retrovector expressing anti-CEA scFv and containing CEACAM1 cDNA (GPEscFv-env/BGPa). After its properties are analysed, GPEscFv-env/BGPa will be applied for infection of CEA-producing tumor cells in vitro and in vivo.
2. When GPEscFv-env containing green fluorescent protein was given to CEA-expressing cells in vitro, fluorescence of the protein was observed in the cells. The same vector containing the suicide gene iNOS induced suppression of the growth of CEA-producing tumor implanted into nude mice, suggesting that this retrovector is able to deliver genes effectively to CEA-expressing cells in vivo, as well as in vitro.
3. The homotypic adhesion activiy of CEACAM1 is expected to be important for its tumorp suppressive activity. Therefore, the structure essential for the cell adhesion activity of CEACAM1 was investigated by preparing CEACAM1 mutants with modified sequences. Four amino acid. residues located in the N-terminal domain of CEACAM1 were identified to be critical to the homotypic adhesion activity of CEACAM1.
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