Expression Of Apolipoprotein D In Esophagus Cancer And Correlation With Prognosis

BackgroundEsophagus cancer has high incidence and mortality rates in global cancer, although in recent years, a grate progress has been made on new diagnostic methods of esophagus cancer, its overall survival in 5 year survival is only 3% to 10%. Among the clinical follow-up of the high incidence area in Henan, our team found that many advanced cancer patients can survival with tumors for a long time. Belong to the same period, the life have such a big difference, this prompted that there may be some limitations when we evaluate the prognosis and outcome of esophagus cancer rely on TNM staging. Thus, find a new biomarker to reflect the prognosis of esophagus cancer is the new struggle target. According to the research, apolipoprotein D was closely linked with many tumor factors, involved in the occurrence, development and prognosis of a variety of tumors, which may include esophageal cancer.ObjectiveFind candidate apolipoprotein D, and by comparing the expression level of this protein in preoperative serum and organization in different survival stage of esophageal cancer patients, to discusses its relevance to the prognosis of the disease, then we can Look for biomarkers of esophageal cancer prognosis, and provide reference for clinical diagnosis and risk prediction.Methods1. Case selection and grouping:We retrieved the 731 patients in a cancer hospital of high incidence area,organized their preoperative serum specimens and clinical pathological information, and Sorted out their esophageal carcinoma tissue and normal esophageal mucosa. Then we telephone follow-up and family follow-up all of the patients or their family members,the follow-up period ended in September 2013 and the survey results were entered into the computer. After following the inclusion and exclusion criteria of patient data and samples ,Random extraction from the data bank of survival period less than 3 years and survival period more than 5 years, each of them are 34 patients, and add 10 healthy people who have a physical examination as a normal control group.2. Screening of differentially expressed proteins:By iTRAQ joint MALDI-TOF/TOF MS (MALDI-TOF/TOF MS) to comparatively analyze the protein expressed in serum of esophagus cancer patient, and Combined literature, then by hierarchical clustering analysis heatmap, lock destination apolipoprotein D.3. Serum verification: Using Western blot technique to observe the expression differences of apolipoprotein D in serum of different survival patients and normal serum, verify the early conclusion of iTRAQ joint MALDI-TOF/TOF MS.4. Organization authentication: Then by immunohistochemical SP method to observe the expression of apolipoprotein D in serum of different survival patients and in normal serum.Results1. The use of iTRAQ combined MALDI TOF/TOF MS, in view of the survival period of 3 years or less and survival period of 5 years or more in patients with esophageal cancer esophagus cancer serum protein expression were analyzed. A total of 556 kinds of proteins in this experiment a detailed quantitative information, which has significant difference of protein expression there are 253 species,52 of this kind of protein expression with the extension of the lifetime and rise,48 kinds of protein expression with the extension of survival and cut. apolipoprotein D is 52 of the expression protein, one of its conditions show that the protein expression and esophageal EC long-lived was significantly positive correlation.2. Western blot technique observed that apolipoprotein D expressed highest in normal human’s serum, the survival period more than 5 years come after, and the survival period less than 3 years is the lowest. Compare the survival period of more than 5 years with the normal people, Compare the survival period of more than 5 years with the survival period of less than 3 years, the difference of OD were statistically significant P<0.01).3. The IHC method shows that apolipoprotein D express high in normal esophageal squamous epithelium, but lower in cancerous tissue, in which, the survival period of more than 5 years is higher than the survival period of less than 3 years; Compare the survival period of more than 5 years with the normal esophageal tissue, the difference of OD was statistically significant(P<0.01); Compare the survival period of more than 5 years with the survival period of less than 3 years, the difference of OD was also statistically significant(P<0.05).ConclusionThe expression of ApoD in the survival period of more than 5 years is higher than the survival period of less than 3 years, no matter in preoperative serum or tissue. ApoD has positive correlation with esophagus cancer.long-lived, can be the biomarkers to predict the prognosis of patients with esophagus cancer.