Objective To investigate the effects of progesterone on the expressions of p57^kip2 and Cyclin E in human endometrioid carcinoma(EC) cells JEC in vitro.

Methods The JEC cells cultured in vitro were treated with high, medium and low concentrations(1×10^-4, 1×10^-6 and 1×10^-8mol/L) of progesterone(P). The untreated JEC cells were taken as control group. After 24, 48, 72h, the light microscope and electron microscope were used to observe the morphological changes of JEC cells. MTT was used to test the growth conditions. Western blot was used to test the protein expressions of p57^kip2 and Cyclin E in JEC cells.

Results MTT, light microscope and electron microscope results showed medium and low concentration of progesterone could promote JEC cells growth (P < 0.05), but high concentration of progesterone could inhibit the growth of JEC cells(P < 0.05). Western blot result showed: (1) when JEC cells were treated with progesterone for 48 and 72h, the protein expression of p57^kip2 was increased with the increase of progesterone concentration (P > 0.05) while the protein expression of Cyclin E was decreased (P < 0.05); (2) at the same concentration of progesterone, the protein expression of p57^kip2 in the high, medium and low concentration groups were progressively increased with the extension of time (P < 0.05), while the protein expression of Cyclin E were progressively decreased in the high and medium concentration groups (P < 0.05); the positive expression rates of p57^kip2 and Cyclin E were negatively linear regression relation (P < 0.05).

Conclusion In the occurrence and development of EC, progesterone could regulate the protein expressions of p57^kip2 and Cyclin E.