Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
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Research Abstract |
The NTera 2 (NT2) cell line is a teratocarcinoma derived from a human embryonal carcinoma (BC) cell line that has the capacity to form bulky tumors that are lethal within 70 days after transplantation into subarachnoid space, superficial neocortex, and ventricle in the adult nude mouse brain. However, when confined to the caudoputamen (CP) in adult nude mouse brain, NT2 cells stop dividing and differentiate into postmitotic mature neurons. To determine if this phenomenon is developmentally regulated, we transplanted NT2 cells into the mouse brain at postnatal days (P)0-21 (P0-P21). Transplantation of NT2 cell into the CP of neonatal brain at P0-P4 resulted in the rapid formation of bulky tumors and most of the grafted mice died within 5-40 weeks after implantation. Although older neonatal (P7, P12) mice with similar CP grafts of NT2 cells survived longer than P0-P4 mice, NT2 cells still were tumorigenic in these older mice. These neonatal mice under P12 had bulky tumor located in subarachnoid space and ventricle. In contrast, NT2 cells transplanted into the CP of pups at P14, P16 and P21 behaved like NT2 cell grafts in the adult mouse CP. BrdU-positive NT2 cell was stained in dark on the nuclei. The BrdU-labeling index (BrdU-LI) of NT2 cells, cocultured with the CP, arachnoid membrane, neocortex, and cerebellum of mice, was 42.14±5.22 (mean ± standard deviation), 47.20±8.26, 44.08±11.8 and 41.74±3.54 respectively. No significant differences were observed among them. On the other hand, that of the control was 42.77 ア 5.12. No significant differences were observed between them compared with the control. Statistical analysis was not much differences among the different region, however, the Brd-U LI of NT2 cells cocultured with arachnoid menbrane was higher than other region. These data suggest that developmentally regulated factors exist in the adult mouse CP but not neonatal mouse brain.
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