不同生存期食管鳞癌患者载脂蛋白D表达水平的研究

Expression of apolipoprotein D in esophageal squamous cell carcinoma patients with different survival terms

目的:通过对不同生存期食管鳞状细胞癌患者术前血清及组织中载脂蛋白D(ApoD)表达水平差异的研究,探讨其与该病预后的相关性,推测其是否可能成为预测食管癌患者预后的生物标记物。方法:收集河南省食管癌高发地区安阳市肿瘤医院2008年3月至2009年9月行根治性切除食管癌的患者731例,选择一般资料、血清标本及组织标本建立资料库;随机从资料库抽取生存期≤3年和生存期≥5年的两个极端生存期患者各34例作为研究对象,以健康人群作为正常对照组,使用同位素标记相对和绝对定量法(isobaric tags for relative and absolute quantification,iTRAQ)联合基质辅助激光解吸离子化串联飞行时间质谱(MALDI-TOF/TOF MS)蛋白质组学技术对食管癌患者术前血清蛋白进行分析比照,锁定目的蛋白ApoD;采用Western blot技术验证ApoD在不同生存期食管鳞癌患者术前血清及健康人群血清的表达水平;使用免疫组织化学技术观察不同生存期食管癌组织及正常组织中ApoD的表达水平。结果:iTRAQ联合MALDI-TOF/TOF MS结果显示,有52种蛋白的表达随生存期延长而上调,具有显著性差异,ApoD是其中之一。Western blot结果显示ApoD在生存期≥5年组血清中表达最高,正常人血清中表达其次,而在生存期≤3年组中表达最低,差异均有统计学意义(P<0.05)。免疫组织化学结果显示ApoD在正常食管鳞状上皮中表达最高,在生存期≥5年组表达其次,在生存期≤3年组中表达最低,差异均有统计学意义(P<0.05)。结论:ApoD表达水平与食管癌患者的生存期呈正相关,可能与食管癌患者的预后相关,可能成为预测食管癌患者预后情况的一种生物标记物。

Objective:To investigate ApoD expression in preoperative serum and tissues of patients with esophageal squamous cell carcinoma of different survival terms,to explore its correlation with disease prognosis,and to speculate whether it can act as a biomarker for predicting the prognosis of patients with esophageal cancer.Methods:A total of 731 patients with radical resection of esophageal cancer were collected from Anyang Tumor Hospital in an area of high incidence of esophageal cancer in Henan Province from March 2008 to September 2009.General data,serum samples,and tissue specimens were collected.Patients with two extreme survival terms(34 cases)-a survival period≤3 years and a survival period≥5 years were randomly selected from the database,and the healthy population was used as the normal control group.iTRAQ combined with MALDI-TOF/TOF MS was used to analyze the preoperative serum proteins in patients with esophageal cancer and lock the target protein ApoD.Western blot analysis was used to verify the level of ApoD expression in preoperative serum and healthy individuals with esophageal squamous cell carcinoma of different survival terms.Immunohistochemical techniques were used to detect the expression level of ApoD in esophageal cancer tissues and normal tissues.Results:The results of iTRAQ combined with MALDI-TOF/TOF MS showed that the expression of 52 proteins was up-regulated with prolonged survival,and the difference was significant;ApoD was one amongst them.Western blot results showed that ApoD had the highest serum expression in the≥5 years survival group,followed by normal human serum,and the lowest expression in the group having survival period≤3 years.The difference was statistically significant.Immunohistochemistry results showed that ApoD exhibited the highest expression in normal esophageal squamous epithelium,followed by the≥5 years survival group,and lowest in the≤3 years survival group.The difference was statistically significant.Conclusions:The expression of ApoD is positively correlated with the survival of patients with esophageal cancer,which may be related to the prognosis of patients with esophageal cancer.Thus,ApoD could be a potential biomarker for predicting the prognosis of patients with esophageal cancer.