LP1-1 세포에서 cAMP에 의한 증식 촉진 인자의 발현 조절 = Effect of cAMP on the Maturation Promoting Factor in LP1-1 cells

다국어 초록 (Multilingual Abstract)

The present study examines cell cycle distribution and effects of cAMP on MPF regulation involved in cell cycle progression in LP1-1 cells. The cell cycle distribution of LP1-1 cells analyzed by ³H-thymidine incorporation rate and FACS showed G1 phase in 0-10hr, S in 10-18h, G2/M in 18-21hr after release from G1/S boundary. At each phase of cell cycle, expression of cyclin D1 and D3 were examined. Expression of cyclin D1 was induced in mid-G1 and increased with time until S phase and then decreased at a corresponding to G2/M phase. The level of cyclin D3 mRNA was also elevated until S phase and declined at G2/M phase. cAMP has an inhibitory effect on the cell proliferation in LP1-1 cells and the expression of cyclin D1 anxd D3 genes were decreased at G1 phase company to those of control. In addition, cAMP analogues were treated to the G0/G1 arrested cells, DNA synthesis were examined by the late of[³H]-thymidine incorporation for 30min at S phase(12hrs after release). The results show that DNA synthesis was decreased to 25-40% of control. After treatment of cAMP, G0/G1 arrested cells also show a similar pattern with G1 arrested cells as to growth-ingibitory effect by cAMP. These results indicate that cAMP may inhibit the cell proliferation by decreasing the expression of D-type cyclin genes in mouse fibroblast LP1-1 cells.