|Budget Amount *help
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2001: ¥1,500,000 (Direct Cost: ¥1,500,000)
1: To investigate the differential roles of cdk2 and cdk4, 3T3 cell lines with stably expressing dominant negative cdk2 (cdk2dn) and dominant negative cdk4 (cdk4dn) were established. GuS transition were delayed by two hours in both cell lines when cell cycle was stimulated by serum stimulation. In cdk4dn cells, both of cdk2 and cdk4 kinase activities were reduced, but only cdk2 activity was reduced in cdk2dn cells. In the serum starved condition, cdk4dn cells were more sensitive to apoptosis compared to parent 3T3 cells, but cdk2dn cells were not. These results indicate that both of cdk2 and cdk4 are involved in G1/S cell cycle progression, but onlycdk4 is important in cell survival signal induced by serum stimulation. On the contrary, 3T3 cells with stably expressing dominant negative cdk6 (cdk6dn) showed no delay in G1/S transition. These date indicate that cdk4 and cdk6 have different biological roles, although they are considered to have redundant functions in the cell cycle progression.
2:IL2-dependent allo-specific CTL lines against wild type p53 expressing A2058 melanoma cells were established. To investigate the relevance of p53 and NFkB to the cytolytic signals, cytotoxicity against A2085 with mutant p53 and dominant negative 1kB was compared to that against parent A2085. There were no significant differences in cytotoxicity between these cell lines. Considering that the amount of secreted granulysin, which is a cytolytic effector molecule, is equal, p53 and NFkB are possibly not involved in the death signals induced by CTL.