NIH3T3细胞不同增殖时相c－fos和c－jun癌基因表达的动态分析

ＮＩＨ３Ｔ３细胞经血清刺激由静止期进入Ｇ１期，提取该期不同时相细胞的总体ＲＮＡ，并提取同步化于Ｇ１、Ｓ、Ｇ２和Ｍ期细胞的总体ＲＮＡ，分别与ｃ－ｆｏｓ（２．１ｋｂ）和ｃ－ｊｕｎ（１．８ｋｂ）基因探针进行斑点杂交。结果显示２个癌基因除了在血清刺激后１ｈ都出现ｍＲＮＡ聚集高峰外，ｃ－ｊｕｎ还在血清刺激后１６ｈ时出现第２个聚集峰，生长期细胞在细胞周期各时相均只有ｃ－ｆｏｓ基因的少量表达，而ｃ－ｊｕｎ在Ｓ期的表达量明显高于其他各期。说明ｃ－ｆｏｓ和ｃ－ｊｕｎ除了在细胞进入生长周期时发挥基因调控功能外，ｃ－ｊｕｎ还可能在晚Ｇ１／Ｓ期产生作用，这种作用不需ｃ－ｆｏｓ蛋白的参与。

The Analysis of c-fos and c-jun Oncogenes Expression in Different Phases of NIH3T3 Cell Cycle Progression

NIH3T3 cells' total RNA was extracted at various lengths of time after the cells were induced to re-enter the cell cycle from quesent stage by serum stimulation and at G₁,S,G₂ and M phases synchronized by double thymidine block and colcemid block.These samples were then analyzed by dot hybridization to determine the levels of c-fos and c-jun mRNA.Our results show that the peaks of c-fos and c-jun mRNA accumulation were found at 1 h after serum stimulation.Besides,it shows a second c-jun mRNA accumulation peak at 16h after serum stimulation.For the continuous growing cells,c-fos was found to be in low expression in every phases of cell cycle,whereas c-jun was found to have a high level of expression in S phase.These results suggest that in addition to the associated function of c-fos and c-jun in cells which are entering cell cycle,c-jun protein may play a unique role in G₁/S phase which does not need c-fos protein to cooperate with.