|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1992 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1991 : ¥1,100,000 (Direct Cost : ¥1,100,000)
1, A pluripotent human embryonal carcinoma cell line (NEC-14) could be induced to morphologically differentiate by treatment with 10^<-2> M HMBA in vitro. To clarify the differentiating lineage, we examined the changes in cell surface antigens, lectin-binding sites, intermediate filaments, and extracellular matrix and secreted proteins. The most distinct changes in antigen expression were the induction of major histocompatibility antigens, HLA-A,B,C, and the changes of stage-specific embryonic antigens, from SSEA-1^-/SSEA-3^+ to SSEA-1^+/SSEA-3^-. Vimentin, a well-known mesenchymal intermediate filament, could be detected only after the differentiation, suggesting that NEC-14 cells were differentiated by HMBA treatment into mesenchymal elements of embryonal mesoderm.
2, The expression of several cellular oncogenes in the NEC-14 cells was also examined. The level of N-myc expression was the highest in undifferentiated cells, but decreased transiently shortly after the HMBA treatment to less than 1/10 of the original level. Several NEC-14 transformants constitutively expressing exogenous N-myc gene were established. Compared with the parental NEC-14 cells, these transformants show d quite different properties, for example, higher plating efficiency, shorter population doubling times, and increased tumorigenic potentials, indicating that additional N-myc genes confer the more transformed state on the cells.
3, From the human teratocarcinoma cell line PA-1, we established a clonal line, PA-1/NR, that stably produced a distinct cellular arrangement of neural rosettes when cultured as in vitro multicellular spheroids. The rosette formation accompanied a strikingly polarized and overlapped deposition of extracellular matrix components including laminin and type IV collagen.