The Study On The Relationship Between Nuclear Receptor Coactivator AIB1, ER, PR And Their Expression In Endometriosis

Objective:To study the expression of AIB1(amplified in breast cancer 1)in eutopic and ectopic endometrium in patients who suffered from endometriosis(EMs),as well as to analyze the relationship with the expression of ER,PR,And to explore the pathogenesis of endometriosis.Methods:Using immunohistochemistry method,we respectively examined the expression of AIB1,ER and PR in eutopic and ectopic endometrium of 45 EMs cases(study group),and in the 42 normal endometrium(control group).Image dissector showed that the absorbance (A) represented its expression intensity,and SPSS12.0 and PPMS 1.5 were used to analyze variability and correlation.Results:1.The endometrial glands and stroma were observed in all groups. AIB1 positive staining granules appeared brown,and distributed in cytoplasma of glandular epithelium cells and some nucleus;ER, PR positive staining granules located on nucleus of glandular epithelium cells,small amounts on stroma.2.The expression of AIB1 in 3 groups:The expression of AIB1 in eutopic and ectopic endometrium with EMs was significantly higher than that in the endometrium of control group(P＜0.01).3.The expression of ER,PR in 3 groups:Compared with the control group,ectopic endometrium had lower ER and PR levels.(P＜0.01). In EMs patients,the eutopic endometrium had higher levels of ER than that of ectopic tissue.(P＜0.05)4.In the menstrual cycle,there appeared a periodic regularity of the levels of AIB1 and ER in the normal endometrium(P＜0.01),while in the patients with EMs,the expression of AIB1 and ER were detected both in proliferative phase and secretary phase which were not related to menstrual cycle.5.There appeared a negative relationship between AIB1 and ER in ectopic endometrium(r=-0.712,P＜0.01).Conclusion: 1.The expression level of AIB1 in the ectopic endometrium of EMs was significantly higher than that in normal endometrium. Overexpressed AIB1 might enhance the transcriptional activity and stability of ER.This suggests that the abnormal overexpression of AIB1 was closed related to the improvement of estrogen sensitivity, to make the endometrial cells proliferate.Consequently,ectopic implantation and growth could be achieved.2.The expression of ER and PR in ectopic endometrium is significantly lower than that in control group,which might have relationship with the metabolic disturbance and the specific effect of estrogen in the part of ectopic endometrium.This leads to the ectopic focus continuingly grows without becoming mature.3.The difference of biological characteristics between the eutopic endometrium and the normal endometrium might be the pathogenic factor of EMs.4.The overexpression of AIB1 was correlated to negativity of ER in the course of EMs,and the overexpression of AIB1 might enhance transcription in the situation of low level of ER,consequently to promote the EMs.