The Expression And Clinical Significance Of Signal Transducers And Activators Of Transcription 2 In Gastric Adenocarcinoma

BACKGROUND:Gastric cancer is the most common malignant tumor of the digestive system, the growth and development of patients with gastric adenocarcinoma may be correlated with single or multiple gene mutation. Screening and identification of key genes associated with the formation and development of gastric cancer will be helpful to the early diagnosis and prevention of gastric cancer. Signal Transducers and Activators of Transcription 2(STAT2)is a member of the signal transducers and activators of transcription family, closely related with tumor angiogenesis, tumor proliferation and apoptosis. It plays a crucial role in tumor interferon therapy. After a preliminary microarray screening, we found that the expression of STAT2 was closely related to gastric adenocarcinoma. Therefore, the STAT2 expression in gastric adenocarcinoma was observed by immunohistochemistry staining assay to explore its clinical significance and molecular mechanisms in the occurrence and development of gastric cancer,study the relationship between STAT2 expression and clinical biological characteristics of patients with gastric adenocarcinoma. METHODS:The expression of STAT2 in89 cases of gastric adenocarcinoma tissues was detected by immunohistochemical staining assay. Using Wilcoxon signed rank test, we detected the differential expression of STAT2 in gastric adenocarcinoma tissues and pericarcinomatous tissues, and explored molecular mechanisms in the occurrence and development of gastric cancer. Using chi-square test, we analyzed the relationship between the expression of STAT2 and clinical biological characteristics of patients with gastric adenocarcinoma. We evaluated overall survival(OS)-related prognostic factors with Cox univariate and multivariate analysis. We estimated OS at different times, calculated the median survival time, and drew survival time curve with Kaplan-Meier method and function curves on variable factors and survival time with log-rank method. RESULTS:The expression of STAT2 was significantly lower in gastric adenocarcinoma tissues than pericarcinomatous tissues(Z =-6.767, P = 0.000). As for the cellular localization,STAT2 was mainly localized in the nucleus. The expression of STAT2 was correlated with their gender, its expression in female is higher than that of it in men(X2 = 5.192, P = 0.023).The expression of STAT2 had no obvious correlation with age, tumor size, pathological grade, T stage, depth of invasion, lymph node metastasis, lymph node stage, clinical TNM stage(P > 0.05). We revealed that the expression of STAT2, age, gender and pathological grade were not the risk factors for postoperative survival time. However their postoperative survival time was obviously correlated with tumor size, depth of invasion, lymph node metastasis, T stage, clinical TNM stage, lymph node stage(P< 0.05). CONCLUSIONS:The expression of STAT2, mainly localized in the nucleus, was significantly lower in gastric adenocarcinoma tissues than pericarcinomatous tissues. The expression of STAT2 was correlated with their gender. Its expression in female is higher than that of it in men. The postoperative survival time had correlation with tumor size, depth of invasion, lymph node metastasis, T stage, clinical TNM stage and lymph node stage.