【摘要】 目的探讨突触融合蛋白6(STX6)表达水平与肝细胞癌(肝癌)患者临床病理参数的关系,评估STX6在肝癌预后评估中的价值。方法通过TCGA公共数据库获得371例肝癌组织和肝癌旁组织STX6的表达数据及临床资料,分析STX6在肝癌组织及肝癌旁组织中的表达差异及对肝癌患者的预后影响。使用实时定量PCR检测58例肝癌患者的新鲜冷冻肿瘤组织样本及肝癌旁组织的STX6 mRNA表达水平。采用蛋白免疫印迹法检测8例肝癌患者的肿瘤组织和肝癌旁组织、正常肝细胞LO2和7种人肝癌细胞系细胞STX6蛋白表达差异,免疫组织化学染色(免疫组化)法观察肝癌患者的肿瘤组织和肝癌旁组织STX6蛋白染色差异,根据STX6 mRNA表达水平分为STX6低表达组与STX6高表达组,分析肝癌患者STX6 mRNA表达与临床病理参数和肝癌生存预后的关系,并建立Cox回归模型判断STX6对肝癌患者预后的影响。结果 TCGA数据库的基因芯片及临床数据分析显示,371例肝癌组织的STX6 mRNA表达水平高于肝癌旁组织(P <0.001),并且肝癌组织STX6 mRNA表达水平随肿瘤临床分期(Ⅰ～Ⅲ期)及病理分期(G1～G3期)升高而升高(总体及组间两两比较P均<0.05),STX6高表达组肝癌患者总生存率低于STX6低表达组(P <0.05)。58例肝癌组织中STX6 mRNA表达水平高于肝癌旁组织(P <0.05)。进一步分析显示,STX6高表达者的肿瘤分化程度较低、肿瘤较大、美国癌症联合委员会(AJCC)分期较高(P均<0.05)。蛋白免疫印迹显示,肝癌组织中STX6蛋白表达较肝癌旁组织升高(8例标本中有6例提示高表达)。7种不同肝癌细胞系细胞中的STX6蛋白表达均较人正常肝细胞升高。免疫组化也显示STX6在肝癌组织中的表达高于肝癌旁组织,并且主要在细胞质中表达。STX6高表达组肝癌患者的整体生存率低于低表达组(P=0.039)。Cox回归分析显示,AJCC肿瘤分期(HR=5.454,95%CI 1.825～16.297,P=0.002)和STX6 mRNA表达水平(HR=3.872,95%CI 1.641～9.140,P=0.002)与肝癌术后总生存率密切相关。结论 STX6水平可以作为评估肝癌的预后分子标志物。更多还原

【Abstract】 Objective To investigate the correlation between the expression of syntaxin 6(STX6) and clinicopathological parameters of patients with hepatocellular carcinoma(HCC), aiming to evaluate the value of STX6 in predicting the clinical prognosis of these patients. Methods The STX6 expression level and clinical data of 371 HCC patients and matched tissues surrounding hepatoma were obtained from TCGA public database. The STX6 expression levels between HCC and tissues surrounding hepatoma were analyzed and its prognostic value for HCC patients was evaluated. Next, the expression levels of STX6 mRNA in the fresh frozen HCC tissues and tissues surrounding hepatoma from 58 HCC patients were quantitatively detected by realtime quantitative PCR. The expression levels of STX6 protein in the HCC and tissues surrounding hepatoma from 8 HCC patients, normal liver cell LO2 and 7 types of human liver cancer cell lines were detected by Western blot. The staining of STX6 protein in the HCC and tissues surrounding hepatoma was assessed by immunohistochemistry. All patients were divided into STX6 low-and high-expression groups according to the expression of STX6 mRNA. The relationship between STX6 mRNA expression and clinicopathological parameters and clinical prognosis of HCC was analyzed. Finally, a Cox’s regression model was established to determine whether STX6 could be used as an independent factor affecting the clinical prognosis of HCC patients. Results TCGA database demonstrated that the expression levels of STX6 mRNA in the HCC tissues were significantly higher compared with those in the tissues surrounding hepatoma(all P < 0.001). The expression level of STX6 mRNA was significantly up-regulated along with the clinical staging(stage Ⅰ-Ⅲ) and pathological staging(stage G1-G3)(all P < 0.05). The overall survival(OS) of patients with higher STX6 expression was significantly shorter compared with their counterparts with lower STX6 expression(P < 0.05). The expression level of STX6 mRNA in the HCC tissues was significantly higher than that in the tissues surrounding hepatoma(P < 0.05). Patients with higher STX6 expression presented with lower tumor differentiation grade, larger tumor size and higher AJCC cancer staging(all P < 0.05). Western blot showed that the expression of STX6 protein in the HCC tissues was up-regulated than that in the tissues surrounding hepatoma(6 of 8 cases with high expression). The expression levels of STX6 protein in 7 types of human liver cancer cell lines were up-regulated than that in hepatocyte line LO2. Immunohistochemistry indicated that the expression of STX6 in the HCC tissues was higher than that in tissues surrounding hepatoma, primarily expressed in the cytoplasm. The OS of HCC patients with higher STX6 expression was remarkably shorter than that of those with lower STX6 expression(P = 0.039). Cox’s regression analysis showed that AJCC cancer staging(HR = 5.454, 95%CI 1.825-16.297, P = 0.002) and expression of STX6 mRNA(HR = 3.872, 95%CI 1.641-9.140, P = 0.002) were significantly correlated with postoperative OS of HCC patients. Conclusion STX6 expression level can serve as an independent prognostic factor for HCC patients.更多还原