The Expression And Clinical Significance Of Tyrosine Phosphatase SHP2 And Scaffold Protein Gab2 In Endometriosis

Background: Endometriosis is a common gynecological disease characterized by the persistence and growth of vascularized endometrial tissue at ectopic sites with symptoms of dysmenorrhea,infertility,whose mechanisms are still poorly understood.Protein tyrosine phosphatase SHP2 and its upstream scaffold protein Gab2 have important roles in signal transduction.However,the expression,fuction and clinical significance of SHP2 and Gab2 in endometriosis is largely unknown.Objective: To investigate the expression and localization of SHP2 and scaffold protein Gab2 in endometriosis,and to explore its association with clinical characteristics.Methods: The patients with ovarian endometriosis and patients with fibroids who received hysterectomy were enrolled as study participants from January 2017 to September 2018 in Women's hospital,Zhejiang University School of Medicine.The ectopic endometrium and eutopic endometrium of patients with ovarian endometriosis were collected as ECE group and EUE group.The normal endometrium of patients with fibroids who received hysterectomy were collected as control(CE group).The sociodemographic characteristics including age,education level,place of residence and clinical characteristics including dysmenorrhea degree,r-AFS classification,serum CA125 level,past history were collected for all participants.RT-q PCR was used to detect the m RNA level of SHP2 and Gab2 in three groups.The protein expression of SHP2 and Gab2 was detected by Western blot.The expression and localization of SHP2 and Gab2 in endometrium was detected by immunohistochemistry.The differences of SHP2 and Gab2 expression in ectopic,eutopic and normal endometrium were compared.The associations between the expression of SHP2,Gab2 and clinical indexes were explored,respectively.The correlation between SHP2 and Gab2 expression endometrium in was analyzed.Results: According to the inclusion and exclusion criteria,77 participants were included in the study,including 45 patients with ovarian endometriosis and 32 patients as control.The endometrium samples were collected from 45 cases in ECE group,29 cases in EUE group and 32 cases in CE group,with a total sample size of 106 cases.The median(P25 P75)age was 42(33 47)years for all,35(28 42)years for the ovarian endometriosis group,and 47(45.25 50)years for the control group was.The differences of age between the ovarian endometriosis group and the control group were significant(P < 0.001).SHP2 m RNA level was significantly higher in ECE group than in EUE group and CE group(P = 0.006).Western blot showed that SHP2 protein level was higher in ECE group than in EUE group and CE group,and the expression in EUE group was higher than that in CE group(P <0.05 for all).The results of immunohistochemistry showed that SHP2 protein was specifically immunolocalized in the cytoplasm and cell membrane of endometrial glandular epithelial cells.The positive rate of SHP2 was 93.3%,93.1% and 53.1% in ECE,EUE and CE groups,respectively,whose difference was statistically significant(P < 0.001).SHP2 expression was not significantly different in the proliferative and secretory phases(P = 0.130).The expression of SHP2 protein in ectopic endometrium of patients with endometriosis was not affected by age and r-AFS stage,and had no correlation with serum CA125 level and infertility(P > 0.05 for all),but had significant difference in patients with different degrees of dysmenorrhea(P = 0.008).The difference of Gab2 m RNA level was not statistically significant among ECE,EUE and CE groups(P > 0.05).The expression of Gab2 protein in ECE group was significantly higher than that in EUE and CE group(P <0.05),but there was no significant difference between EUE and CE group(P >0.05).Gab2 protein was immunolocalized in endometrial glandular epithelial cells and endometrial stromal cells.The positive rate of Gab2 was 91.1%,93.1% and 46.9% in ECE,EUE and CE groups,respectively,whose difference was statistically significant(P < 0.001).The expression of Gab2 was higher in the secretory phase than in the proliferative phase(P = 0.007).There was no correlation between SHP2 positive grade and age,r-AFS classification,serum CA125 level,dysmenorrhea degree and infertility(P >0.05).There was a significant positive correlation between Gab2 positive level and serum CA125 level(Spearman ? 0.326,P =0.046).The Gab2 expression was not associated with age,r-AFS classification,dysmenorrhea and infertility(P > 0.05 for all).There was a significant positive correlation between SHP2 and Gab2 immunohistochemical expression in endometrial tissues(Spearman ? 0.655,P < 0.001).Conclusions: SHP2 was expressed in glandular epithelial cells of endometrium.The expression of SHP2 in ectopic endometrium was higher than that in eutopic endometrium and normal endometrium.Gab2 was expressed in glandular epithelial cells and stromal cells of endometrium.The expression of Gab2 was higher than that in eutopic endometrium and normal endometrium.There is a positive correlation between SHP2 and Gab2 protein expression in endometriosis.Elevated expressed SHP2 and Gab2 may be involved in the pathogenesis of endometriosis.