The Expression Of Livin And Its Relationship With The Expression Of Smac In Endometriosis

ObjectiveEndometriosis(EMs)is defined as the presence of viable endometrial tissue outside of the uterine cavity.It is a common gynecologic disease.Although it is benign, it is in common with malignancy in propagation,apoptosis,angiogenesis and invasion. Its morbidity has increased in recent years.So far,its aetiology and pathogenesis have not been made clear completely,and it has no specific therapy,so endometriosis is regarded as one of the incurable gynecologic diseases.More and more investigators discussed the aetiology of endometriosis at the angle of tumorigenesis believe that endometriosis is associated with apoptosis closely.The spontaneous apoptosis of endometrial cells is the critical factor to keep the endometrial cells' structure and function normal.Despressed apoptosis can accelerate the occurrence and development of endometriosis and is the important causation why endometrial cells have the ability to grow on unusual position.Livin which can restrain apoptosis is a novel human inhibitor of apoptosis protein (IAPs)family member with oncogene potentiality recently discovered.Livin can hinder apoptosis induced by several ways from its BIR frame bonding with caspase which is the central substance of apoptosis to restrain it's activity,expecially caspase-3,-7,-9's. Smac is recently identified as a new apoptogenic factor that is released from mitochondria.It has the same frame with caspase.It promotes apoptosis by antagonizing inhibitor of apoptosis proteins(IAPs).Smac combines with the BIR frame of IAPs to dissolve its' restraint on caspase.In order to investigate the possible mechanism of Livin and Smac in endometriosis, to clarify the possible mechanism of endometriosis,to offer the experimental basis for biological treatment of endometriosis,the expression of Livin and Smac in tissues from the eutopic endometrium,the ecopic endometrium,and normal endometrium were detected by using SP immunohistochemistry stain. MethodsA total of 104 tissues samples were used in this study,including 40 samples of ectopic endometrium and 34 samples of eutopic endometrium of patients with endometriosis,and 30 samples of normal endometrium tissues.Using streptavidinbiotin peroxidase(SP)method of the immunohistochemistry,we examined the expression of the proteins Livin and Smac in these tissues and analysed their relevance.The clinical materials of EMs were summarized to study the relationship between the two indexes (Livin and Smac)and the staging of EMs.Statistical analysis was performed by using SPSS13.0 statistics software.Results1.Expression of Livin proteinLivin protein expressed mainly in the cytoplasm of glandular cells.Livin protein was detected in only one normal proliferative endometrium,the expression of Livin protein in both ectopic and eutopic endometrium was higher compared with in normal endometrium,and the expression in ectopic endometrium was higher than in eutopic endometrium,the expression of Livin protein in the three groups above had significant difference(P＜0.001).The menstrual phase had no influence on Livin protein in the eutopic and ectopic endometrium of EMs(P＞0.05).2.Expression of Smac proteinSmac protein expressed mainly in the cytoplasm of glandular cells.The expression of Smac protein in normal endometrium was the highest,in both ectopic and eutopic endometrium was lower compared with in normal endometrium,and the expression in ectopic endometrium was lower than in eutopic endometrium,the expression of Smac protein in the three groups above had significant difference(P＜0.001).The menstrual phase had no influence on Smac protein in the eutopic and ectopic endometrium of EMs(P＞0.05),but the expression of Smac in the secretory phase was higher compared with in the proliferative phase(P＜0.05).3.The correlation between the expression of Livin and Smac in EMsNegative correlation was observed between the expression of Livin and Smac in the ectopic endometrium of EMs(r=-0.890,P＜0.001).4.The relationship between the two indexes(Livin and Smac)and the staging of EMsThere was no correlation between the two indexes(Livin and Smac)and the staging of EMs(P＞0.05).Conclutions1.The persistent high expression of Livin and low expression of Smac during both phases of the cycle in eutopic endometrium suggested that there were some fundamental differences between the eutopic endometrium and normal tissues.The differences might contribute to the survival of regurgitating endometrial cells into the peritoneal cavity and the development of endometriosis.2.Elevated expression of Livin and depressed expression of Smac in ectopic endometrium might have important implications for the survival and proliferation of the ectopic endometrial tissue.3.There was prominent negative correlation between Livin and Smac protein in the ecopic endometrium.Elevated expression of Livin and depressed expression of Smac cooperated with each other to play an important role in the pathogenesis of endometriosis.