[Nongenomic effects of estrogen on extracellular signal-regulated kinases through initiating transient calcium flux in endometrial cancer].

OBJECTIVE

To study the mechanism on extracellular signal-regulate kinases (ERK) signal transduction by calcium influx initiated by combination of estrogen with calcium channels or estrogen receptor in endometrial cancer cell Ishikawa.

METHODS

Confocal test was used to determine the relative calcium mobilization by stimulation of estrodiol together with and without the inhibition of ICI182780 and nifedipine. Western-blotting was used to detect the protein expression of phosphorylated ERK1/2 (P-ERK1/2) in the same condition.

RESULTS

The transient calcium flux initiated by 17β-estrodiol (E2) and a membrane-impermeable conjugate of estrogen and bovine serum albumin (E2-BSA), and the calcium mobilization could be inhibited by ICI182780 and nifedipine in 1 min. In Ishikawa cells, phosphorylation of ERK1/2 was stimulated by E2, and the phosphorylation could not be inhibited by E2 after the combination with ICI182780 in 5 min and in 30 min. The phosphorylation also could not be inhibited by E2-BSA after the combination with nifedipine in 5 min, but in 30 min the phosphorylation was decreased. The phosphorylation of ERK by E2-BSA was decreased by the combination with nifedipine in 30 min.

CONCLUSION

The transient calcium flux initiated by estrogen has an effect on the activation of ERK signal pathway in endometrial carcinoma cells.