[Effect of estradiol benzoate on the heat shock protein 70, 90 expressions in endometrial glandular epithelial cell].
OBJECTIVE
To explore the effect of estradiol benzoate on the expressions of heat shock protein (HSP) 70, 90 in endometrial glandular epithelial cell.


METHODS
Normal endometrial glandular epithelial cells were isolated, and cultured by enzymolysis method and identified by electron microscopy and immunohistochemical analysis. The normal endometrial glandular epithelial cells were treated with culture medium only, estradiol benzoate (10(-9), 10(-8), 10(-7) or 10(-6) mol/L), estradiol benzoate (10(-9), 10(-8), 10(-7) or 10(-6) mol/L) and antiestrogen ICI 182780 (fulvestrant, faslodex, 1 micromol/L) and ICI 182780 only for 6, 12, 18, 24 hours respectively. The dose- and time-related effect of estradiol benzoate and ICI 182780 on the cell growth was measured by mononuclear cell direct cytotoxicity assay (methyl thiazolyl tetrazolium assay), and that on the expression of HSP70 and HSP90 in normal endometrial glandular epithelial cell in vitro was measured by immunohistochemical analysis and computerized image analysis system.


RESULTS
Estradiol benzoate stimulated cell growth in a time- and dose-dependent manner and the effect was attenuated by the antiestrogen ICI 182780. The average cell growth rates of 10(-9), 10(-8), 10(-7), 10(-6) mol/L estradiol benzoate for 24 hours were (170 +/- 9)%, (207 +/- 11)%, (231 +/- 12)%, (257 +/- 10)%, which were significantly higher than those of 6 hours [(117 +/- 13)%, (129 +/- 10)%, (146 +/- 10)%, (176 +/- 6)%, P < 0.05] and that those estradiol + ICI 182780 for 24 hours [(137 +/- 4)%, (145 +/- 10)%, (151 +/- 9)%, (167 +/- 3)%, P < 0.05]. Estradiol benzoate treatment resulted in a time- and dose-dependent increase of the expression of HSP90 and decrease of HSP70 in human endometrial glandular epithelial cell. The expression of HSP90 in 10(-9), 10(-8), 10(-7), 10(-6) mol/L estradiol benzoate for 24 hours were (64.8 +/- 10.7)%, (75.9 +/- 12.6)%, (80.4 +/- 8.2)%, (83.2 +/- 7.6)%, which were significantly higher than that of the control [(28.0 +/- 3.3)%, (29.0 +/- 5.6)%, (29.0 +/- 5.0)%, (30.0 +/- 6.4)%, P < 0.05] and that of estradiol benzoate + ICI 182780 for 24 hours [(28.2 +/- 2.1)%, (29.7 +/- 3.2)%, (35.0 +/- 4.7)%, (34.7 +/- 6.5)%, P < 0.05]. The expression of HSP70 in 10(-9), 10(-8), 10(-7), 10(-6) mol/L estradiol benzoate for 24 hours were (38.4 +/- 5.7)%, (35.3 +/- 4.9)%, (32.5 +/- 3.1)%, (25.3 +/- 6.2)%, which were significantly lower than that of the control. The estradiol benzoate-induced effects on HSP70 levels were not attenuated by the antiestrogen ICI 182780.


CONCLUSIONS
The effects of estradiol benzoate on the cell growth and HSP90 expression are estrogen receptor-dependent and the expression of HSP90 may be beneficial to the cell growth. The effect of estradiol on the expression of HSP70 is estrogen receptor-independent and the expression of HSP70 may protect the cell from damage.
Bai
Xiao-xia
XX
Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Jinan 250012, China.
Wang
Wen-dong
WD
D049109:Cell Proliferation; D002478:Cells, Cultured; D004717:Endometrium / Q000166:cytology / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis*; D018841:HSP90 Heat-Shock Proteins / Q000096:biosynthesis*; D006801:Humans
D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; C074283:estradiol 3-benzoate; D004958:Estradiol