Expression Of CBX8 In Gastric Adenocarcinoma And Its Clinical Significance

Objective Gastric cancer is one of the most common malignant gastrointestinal tumors in China with the highest incidence and mortality.The occurrence and development of gastric cancer is a complex process with multi-factor control,such as tumor invasion and metastasis.CBX8 is a kind of transcription inhibitory factor,which can regulate a variety of biological function.It has been reported that CBX8 protein can regulate X chromosome inactivation,embryonic stem cell differentiation,cell aging and proliferation process,and participate in the occurrence and development of tumor.However,the role of CBX8 in gastric cancer is rarely reported.We will detect the expression of CBX8 in gastric adenocarcinoma and corresponding adjacent normal tissue,and to explore its relationship to clinicopathological features and prognosis,and to provide the theoretical basis for finding new target of treating gastic cancer.Methods The expression of CBX8 protein in 119 pairs primary gastric adenocarcinoma and corresponding adjacent normal tissue was detected by immunohistochemistry using tissue chip.Results There was no significant difference in the expression of CBX8 between the group of chronic superficial gastritis and chronic atrophic gastritis(?~2=0.864,P=0.352).The high expressive rate of CBX8 in gastric adenocarcinoma tissue(46.2%)was obvious significantly higher than that in corresponding adjacent normal tissue(13.4%)(?~2=30.53,P<0.01).The high expression of CBX8 in gastric adenocarcinoma tissue was obviously related to the differentiation,clinical staging,and lymphatic metastasis(?~2=6.445,6.475,4.654,P<0.05,respectively).The high expressive rate of CBX8 in poorly differentiated gastric adenocarcinoma was lower than that in moderately to well differentiated group(?~2=6.445,P=0.017).The high expressive rate of CBX8 in stage I?II group of gastric adenocarcinoma was higher than that in stage???group(?~2=6.475,P=0.014).The high expressive rate of CBX8 in having no lymphatic metastasis group of gastric adenocarcinoma was higher than that in having lymphatic metastasis group(?~2=4.654,P=0.037).The high expression of CBX8 was unrelated to the patient's gender,age,infiltrating depth and tumor size(?~2=1.472,0.282,4.265,1.569,P>0.05,respectively).Kaplan-Meier analysis showed that the patient with higher expression of CBX8 had both longer overall survival time(P=0.004)and disease-free survival time(P=0.004).The two groups above of the median overall survival time was 60 months,46.7 months respectively,and the 5-year survival rate was 73.08%,46.56%respectively.The two groups of the median disease-free survival time was 60 months,39.8 months respectively,the 5-year survival rate was 61.54%,41.38%respectively.In the group of poorly differentiated,the overall survival time of patients with CBX8 high-expression was significant longer compared to those with CBX8 low-expression(?~2=5.354,5.334,P=0.021,0.021).In the group of lymph node metastasis,the overall survival time of patients with CBX8 high-expression was longer than those with CBX8 low-expression(?~2=9.188,9.118,P=0.002,0.003).In the group of TNM stage III and IV,the overall survival time of patients with CBX8 high-expression was significant longer compared to those with CBX8 low-expression(?~2=7.224,7.198,P=0.007,0.007).The single factor analysis showed that all of patients'age,degree of differentiation,clinical stage,lymph node metastasis,tumor size,CBX8 expression level,affected overall survival time(P<0.05).The single factor analysis also showed that all of patients'age,degree of differentiation,clinical stage,lymph node metastasis,tumor size,CBX8 expression level,affected the disease-free survival time(P<0.05).Cox multivariate analysis revealed CBX8 expression,clinical staging and lymphatic metastasis were independent predictors of overall survival time and disease-free survival time(P<0.05).Conclusion 1.The high expressive rate of CBX8 in gastric adenocarcinoma tissue was significantly higher than that in their corresponding adjacent normal tissue,it suggests that the expression of CBX8 may be involved in the tumorigenesis of gastric adenocarcinoma.2.The high expressive rate of CBX8 in gastric adenocarcinoma tissue was obviously related to differentiation,clinical staging and lymphatic metastasis suggests that CBX8 may be associated with the progression of gastric adenocarcinoma.3.The high expression of CBX8 was related to the overall survival time and disease-free survival time of patients with gastric adenocarcinoma,and the high expression of CBX8was one of the independent predictor of prognosis.These results suggest that CBX8expression may be closely related to postoperative survival time.Detecting the expression of CBX8 may have important clinical value for evaluating the prognosis of gastric adenocarcinoma,and it may become a new target for therapy.