ERa and ERK1 2 MAP kinase expression in microdissected stromal and epithelial endometrial cells

Abstract EN

Our previous published data detected higher expression of total and active mitogen activated protein kinase (MAPK) in the epithelial vs.

stromal cells of the endometrium.

In the present work we compared the expression of ERK 1 / 2 MAPK and estrogen receptor a (ERa) in epithelial versus stromal cells in benign human endometrial tissues.

Laser capture microdissection was used to separate glandular epithelium and stromal cells from six frozen, proliferative phase endometrial specimens.

Total and phosphorylated levels for ERK 1 / 2 and ERa were measured by quantitation of signals from Western blots using specific antibodies against the active and total forms of ERK 1 / 2 and against ERa.

When the level of the proteins was quantitated and normalized to b actin from microdissected stroma and epithelium, no significant difference was detected in the levels of these proteins between the two tissue compartments.

There was a trend toward higher expression in the stroma vs.

epithelium, respectively (active ERK 1 / 2 0.45 ± 0.17 vs.

0.2 ± 0.65 ; total ERK 1 / 2 0.54 ± 0.35 vs.

0.28 ± 0.23 ; Era 0.82 ± 0.28 vs.

0.54 ± 0.18 ; n = 6).

These data demonstrate that there are comparable levels of ERa (P = 0.41), total ERK 1 / 2 (P = 0.18) and active ERK 1 / 2 (P = 0.13) in the stroma and epithelium of proliferative phase endometrium with a trend toward higher expression of these proteins in the stromal compartment.