|Budget Amount *help
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2000: ¥900,000 (Direct Cost: ¥900,000)
To investigate the molecular mechanisms by which carcinoma cells metastasize, we have established liver metastatic models. Human gastric carcinoma cell line AZ521 (5 X 10^6/0.1ml) was transplanted orthotopically into the stomach of nude mice using cell suspension technique. Athymic female BALB/c nu/nu mice, 6-7 weeks old, weighing 18-22g were used. After from 6 to 8 weeks, the liver and regional lymph nodes with a few metastatic foci of AZ521 cells were dissected, we established AZH1G and AZL5G. The same procedure was repeated using AZH1G and AZL1G, and AZH5G and AZL5G was established upon the fifth cycle of stepwise selection. We have also established AZ3P3G using intraperitoneally and orthotopically stepwise selection methods. 1) AZL5G produced lymph node mestastasis in 85.0%, and AZH5G produced multiple round liver mestastasis in 87.5%, and AZ3P3G developed peritoneal metastasis in 80.0% of mice. 2) Each metastatic cell grew significantly larger than parental AZ521 in vivo. 3) A cell motility assay demonstrated that the migration ability of each metastatic cell was clearly higher than that of AZ521. 4) The expression of several cell adhesion molecules by FACS analysis showed that the incidence of α_1 and α_2 integrins expression in AZL5G cells was significantly higher than in AZ521. AZH5G cells expressed suggestive up-regulation of α_1, α_2, α_3 and α_5 integrins, and AZ3P3G cells expressed up-regulation ofα_2,α_3,α_5 andα_6 integrins. Moreover, Comprehensive analysis of the biological behavior of highly metastatic cell lines and the less metastatic same parental line were demonstrated the differences in adhesive activity and VEGF production. Above all, our experimental models should be useful for investigation of the mechanisms of metastasis in human gastric carcinoma.