Expression And Clinical Significance Of XIAP In Epithelial Ovarian Cancer Tissues

Background Ovarian cancer is one of the three common malignant tumors of the female reproductive system,including epithelial ovarian cancer accounted for 85%-90% of ovarian malignant tumors,ranked 6th in female malignant tumors,and 5th of the cancer-related death causes.Although the pathogenesis of ovarian cancer remain elusive,increasing researches show that the defect of apoptosis mechanism plays an essential role in its occurrence and development,and the inhibition of tumor cell apoptosis is an important mechanism of ovarian cancer.At normal condition,apoptosis is regulated by genes of autonomic death,which is of great significance for stabilizing multicellular organisms.In recent years,the newly discovered apoptotic inhibitory protein IAPs(inhibitor of apoptosis protein)has been proved to participate in the survival and apoptosis of cells through various means,and strongly influenced the occurrence and prognosis of tumors.X-chromosome-linked inhibitor of apoptosis protein is one of the most important members of the IAP family,which is considered to be the strongest and most functional endogenous aspartate-specific cysteine protease(caspase)inhibitory factor.An accumulating amount of evidence has indicate that XIAP plays an essential role in the occurrence and development of tumor and closely related to its chemotherapy resistance,such as thyroid cancer,breast cancer,lung cancer and prostate cancer.However,there are few studies about the expression and clinical significance of XIAP in epithelial ovarian cancer.Thus,we examine whether the expression of XIAP in normal ovarian tissues,benign ovarian tumor tissues and epithelial ovarian cancer tissues was different and then investigate whether the expression of XIAP in theclinicopathological parameters of epithelial ovarian cancer(clinical staging,pathological type,differentiation degree,lymph node metastasis)was different.We also study whether there is any difference between the expression of XIAP in the chemotherapy-resistant group and the sensitive group of epithelial ovarian cancer.Objects and methods Objects 60 epithelial ovarian cancer samples were collected from Department of Gynecology in Second Hospital Affiliated to Guangzhou Medical University during 2012.10 to 2016.5.50 samples of ovarian benign tumors and 50 samples of normal ovarian tissues of the same period were also collected as the control group.All samples were diagnosed by pathology.Methods The expression of XIAP in normal ovarian tissues,benign ovarian tissues and epithelial ovarian carcinoma tissues was detected by immunohistochemical En Vision Two step method.The expression of XIAP in epithelial ovarian cancer tissues of different clinical staging,pathological type,differentiation degree and lymph node metastasis was detected by immunohistochemical semi-quantitative method.According to FIGO 2015 guidelines,epithelial ovarian cancer tissues were classified into chemotherapeutic sensitivity group and chemotherapy resistance group,and the expression of XIAP in the two groups was detected by immunohistochemical semi-quantitative method.Results 1.Expression of XIAP in normal ovarian tissues,benign ovarian tissues and epithelial ovarian cancer tissuesThe expression of XIAP in normal ovarian tissues: negative(-)38 cases,weakly positive(+)10 cases,positive(+)2 cases,positive rate was 24%(12/50);The expression of XIAP in benign ovarian tumors: negative(-)32 cases,weakly positive(+)6 cases,positive(++)12 cases,the positive rate was 36%(18/50);the expression of XIAP in epithelial ovarian cancer tissues: negative(-)7 cases,weakly positive 16 cases(+),positive 27 cases()++,strong positive(+++)10 cases,positive rate of 88.3%(53/60).XIAP shows a higher expression rate in epithelial ovarian cancer tissues than benign ovarian tumors and normal ovarian tissues.There were significant differences in the expression of XIAP between epithelial ovarian cancer and benign ovarian tumor tissues,as well as epithelial ovarian cancer and normal ovarian(P=0.000 <0.01),but there was no statistical difference between benign ovarian tumor tissues and normal ovarian tissues(P=0.190 >0.05).2.Expression of XIAP in the clinicopathological parameters of epithelial ovarian cancer(clinical staging,pathological type,differentiation degree,lymph node metastasis)The expression of XIAP in the early(I-II period)epithelial ovarian cancer tissues and advanced(III-IV)epithelial ovarian carcinoma is significant differences(P=0.002).Further analysis shows that the expression of XIAP is positively correlated with clinical staging(r=0.404 P=0.001).The later clinical staging,the higher expression of XIAP.There was no significant difference among the expression of XIAP in ovarian serous cystadenocarcinoma,mucous cystadenocarcinoma,clear-cell carcinoma and endometrioid carcinoma(P=0.588).Significant differences were found among the expression of XIAP in low differentiation,middle differentiation and high differentiation epithelial ovarian cancer(P=0.009),further analysis of XIAP expression shows a negative correlation with differentiation degree(r=-0.420,P=0.002).The lower the differentiation,thehigher expression of XIAP.The expression of XIAP increased in low differentiation,middle differentiation,high differentiation epithelial ovarian cancer tissues in turn.There was no significant difference in the expression of XIAP in epithelial ovarian cancer tissues with or without lymph node metastasis(P=0.350).3.Relationship between the expression of XIAP and the sensitivity of platinum chemotherapy and drug resistance of epithelial ovarian cancer The expression of XIAP in chemotherapeutic sensitivity group and chemotherapy resistance group in the epithelial ovarian cancer tissues was significant difference(P=0.023),further analysis shows that XIAP expression and the sensitivity of chemotherapy is negatively correlated(r=-0.295,P=0.022).The lower sensitivity of chemotherapy,the higher expression of XIAP.Conclusion 1.XIAP expression is significantly higher in eptithelial ovarian cancer tissues than in normal ovarian tissue and benign ovarian tissue.2.In epithelial ovarian cancer tissues,the expression of XIAP in the late stage is significantly higher than that of early stage;the expression of XIAP is unrelated to the pathological type and lymph node metastasis of epithelial ovarian carcinoma.3.In epithelial ovarian cancer tissues,the expression of XIAP in the chemotherapy resistance group is significantly higher than the chemotherapy sensitive group.