[Preliminary study of membrane estrogen receptor expression in endometrial carcinoma cells]

To analyze if there are membrane estrogen receptors (ER) in endometrial carcinoma and if there is some relationship between membrane ER and nuclear ER.

The cell membrane and total cell ERalpha and ERbeta expressions of high and moderate differentiation endometrial carcinoma cells (Ishikawa and HEC-1A cells) were analyzed. Intermittent immunofluorescence dyeing and fluorescent microscopy were carried out with the cells treated with polyformaldehyde and Triton X-100. Intermittent immunofluorescence dyeing and flow cytometry were carried out with the live cells and the cells treated with Triton X-100 respectively.

There were fluorescences on the membrane of the Ishikawa and HEC-1A cells which were treated with polyformaldehyde. When the cells were treated with Triton X-100, the fluorescences were also seen inside the cells. The fluorescence intensity of ERalpha and ERbeta in Ishikawa cell membrane (1.09 +/- 0.21, 1.27 +/- 0.33) was stronger than the control, but there were no significant differences (P > 0.05). When treated with Triton X-100, the total cell fluorescence intensity of ERalpha and ERbeta in Ishikawa cell (4.21 +/- 0.34, 4.69 +/- 1.96) was stronger than the membrane (P < 0.05). The ERalpha and ERbeta fluorescence intensity of HEC-1A cell membrane (1.58 +/- 0.13, 1.49 +/- 0.04) were stronger than the control (P < 0.05). The fluorescence intensity of ERalpha and ERbeta of the HEC-1A cell (2.34 +/- 0.33, 2.52 +/- 0.15) was stronger than the membrane also (P < 0.05). The membrane ERalpha fluorescence intensity of Ishikawa was lower than HEC-1A (P = 0.028). But the total cell ERalpha fluorescence intensity of Ishikawa was higher than HEC-1A (P = 0.002).

There are membrane ER on endometrial carcinoma cells Ishikawa and HEC-1A. The membrane ER must have some similarity to the nuclear receptor. There is no direct correlation between the quantity of the membrane ER and nuclear ER.