Expression of apolipoprotein D in esophageal squamous cell carcinoma patients with different survival terms / 中国肿瘤临床

ABSTRACT

Objective: To investigate ApoD expression in preoperative serum and tissues of patients with esophageal squamous cell car-cinoma 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 se-rum 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.