[PP2A is involved in the inhibitory effect of progesterone on proliferation of mouse endometrial epithelial cells].

OBJECTIVE: To study the effect of protein phosphatase 2A (PP2A) in the negative regulation of progesterone on the proliferation of mouse endometrial epithelial cells (EECs). METHODS: Mouse EECs were isolated and cultured in vitro, which were divided into four groups when they grown to confluence: control group (P4) was treated with 1 micromol/L progesterone only, group A, B and C were treated respectively with 1 micromol/L progesterone and different concentrations of okadaic acid (5 nmol/L, 10 nmol/L and 20 nmol/L). After 24 h, the numbers of cells in different phases of the cell cycle were counted with flow cytometry. RESULTS: The effect of OA on mouse EECs was concentration-dependent. Compared with control group of P4, the change of cell cycle procession in group A was not obvious. Lower proportion of cells in G1 and G2/M phase and higher proportion of cells in S phase in group B, higher proportion of cells in G1 and S phase and lower proportion of cells in G2/M phase in group C were observed. CONCLUSION: Adequate dose OA inhibiting PP2A could release the inhibitory effect of progesterone on proliferation of mouse EECs obviously, this suggested that PP2A was involved in the inhibitory effect of progesterone on proliferation of EECs by influencing the process of cell cycle.