Fibroblast growth factor-induced Thymidylate Synthase activity and expression in the serum-starved UMR 106-01 osteoblast cells.
- Author:
Seong Who KIM
1
;
On You HWANG
;
Jae Dam LEE
;
Kyu Young SONG
;
Dong Ho KIM
;
Hea Nam HONG
;
Jae Suk CHANG
;
Kyu Hwang UM
;
Sung Jin LEE
Author Information
1. Department of Biochemistry, University of Ulsan College of Medicine, Asan Institute for Life Sciences, Korea.
- Publication Type:Original Article
- Keywords:
bFGF;
serum starvation;
UMR 106-01 osteoblast cell;
thymidylate synthase;
c-fos
- MeSH:
Blotting, Western;
Cell Culture Techniques;
Cell Cycle;
DNA;
Fibroblasts*;
Immunohistochemistry;
Osteoblasts*;
Polymerase Chain Reaction;
RNA, Messenger;
Starvation;
Thymidylate Synthase*
- From:Journal of Korean Orthopaedic Research Society
2000;3(2):140-147
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: In the present study, the effects of bFGF on the early responses of proliferation of UMR 106-01 osteoblast cells during cell cycle reentry from the latent(G0/G1) to the proliferative periods(S/M) were investigated. MATERIALS AND METHODS: The synchronized cell culture method using the serum starvation was utilized. After the addition of bFGF, the time courses of protein synthesis, DNA synthesis, thymidylate synthase(TS) activity, TS mRNA level and expression of c-fos were determined. RESULTS: 87% UMR 106-01 cells were synchronized to G0/G1 by serum starvation for seven days in the medium containing 0.1% serum. The protein level began to increase 3 hours after bFGF treatment and reached the maximum at 18 hours. TS activity began to increase 3 hours after the bFGF treatment and reached its peak at 6 hours while its mRNA level, determined by quantitative PCR, reached the maximum at 12 hours. The expression of c-fos protein, determined by western blot analysis and immunocytochemistry, increased 3 hours after bFGF treatment. On the contrary, these prominent changes and responses to bFGF were not observed in the case of using non-synchronized cells cultured in the medium containing 10% serum. CONCLUSION: Based on these data it can be concluded that bFGF-induced DNA synthesis in the early proliferative phase is due to increases in both TS activity and mRNA amount and that the increase in c-fos expression and TS activity occur before the increase in TS mRNA level.
