血清APE1蛋白在结直肠癌临床诊断中的作用及意义

Diagnostic value and significance of serum APE1 in colorectal cancer

目的探讨结直肠癌患者血清APE1蛋白的表达及其在临床诊断中的价值。方法利用ELISA法检测本院2010年1月至2015年9月肿瘤中心收治的202例结直肠癌患者和健康体检中心242例健康对照人群血清APE1蛋白的表达水平,通过免疫组化确定相应患者肿瘤组织APE1蛋白的表达特征,同时采用C-12肿瘤蛋白芯片试剂盒检测上述人群CEA的表达水平。分析血清APE1蛋白与肿瘤组织APE1蛋白表达水平及年龄、性别、分期等临床指标的相关性,并绘制受试者工作特征曲线(receiver operating characteristic curve,ROC)评估血清APE1蛋白及CEA在结直肠癌诊断中的应用价值。结果 202例结直肠癌患者中位血清APE1蛋白浓度为0.331(0.007~4.359)ng/mL,显著高于对照组0.091(0~1.374)ng/mL(P<0.01)。Spearman相关分析显示血清APE1蛋白水平与肿瘤组织中APE1蛋白表达呈正相关(r=0.331,P=0.025),而与年龄、性别、分期等指标不相关。ROC曲线显示血清APE1蛋白的AUC为0.799(95%CI=0.756~0.843),灵敏度为76.20%,特异性为76.40%,血清CEA的AUC为0.736(95%CI=0.687~0.785),其灵敏度为51.00%,特异性为99.60%。血清APE1蛋白与CEA联合后其AUC为0.857(95%CI=0.819~0.896),灵敏度和特异性分别为72.30%和91.30%。结论结直肠癌患者血清APE1蛋白水平与肿瘤组织APE1表达呈正相关且较健康对照人群显著增高。血清APE1蛋白可与CEA联合作为结直肠癌辅助诊断的血清学标志物。

Objective To investigate the expression of serum apurinic/apyrimidinic endonuclease 1(APE1) in colorectal cancer and its diagnostic value. Methods A total of 202 patients with identified colorectal cancer admitted in our center from January 2010 to September 2015 were recruited in this study, and another 242 healthy volunteers who took physical examination at the same period served as normal control. Their serum APE1 level was quantified by ELISA. The expression of APE1 protein in colorectal cancer tissues was detected by immunohistochemistry. The expression of carcinoembryonic antigen(CEA) was detected by C-12 tumor protein chip kit. The correlations of APE1 protein levels in the serum and tumor tissues with age, gender, clinical stage and other indicators were analyzed. Receiver operating characteristic(ROC) curve was plotted to evaluate the value of serum APE1 and CEA levels in the diagnosis of colorectal cancer. Results The serum APE1 level was 0.331(0.007~4.359) ng/mL in the colorectal cancer patients, which was significantly higher than that in healthy control [0.091(0~1.374) ng/mL, P<0.001]. Spearman correlation analysis showed that the serum APE1 level was positively correlated with its protein expression in colorectal cancer tissues(r=0.331, P=0.025), but had no relations with age, sex and clinical stages. ROC curve displayed that the area under the curve(AUC) was 0.799(95%CI=0.756~0.843), the sensitivity was 76.20%, and the specificity was 76.40% for serum APE1 level in the diagnosis. While, the AUC value was 0.736(95%CI=0.687~0.785), the sensitivity was 51.00%, and the specificity was 99.60% for serum CEA level. Their combination increased the AUC value to 0.857(95%CI=0.819~0.896), and the sensitivity and accuracy to 72.30% and 91.30%, respectively. Conclusion The serum APE1 level is positively correlated with its expression level in the colorectal cancer tissue, and both are significantly higher than those in the health control. Combined detection of serum APE1 and CEA levels might be considered as serum markers in auxiliary diagnosis for colorectal cancer.