Detection Of Serum APE1 Protein And Auto-antibody And Their Clinical Value In Tumor

ObjectivesTo investigate the clinical value of serum APE1 in predicting the chemotherapeutic responses and clinical outcome in NSCLC patients receiving platinum-containing chemotherapy.In second part,to explore the diagnostic value of APE1 auto-antibodies(APE1-AAbs)in colorectal cancer.Further clarify the clinical significance of serological detection of APE1 and APE1-AAbs.MethodsFirst part,we measured the sera APE1 level of 412 NSCLC patients and 523 healthy control with a newly established sensitive and specific enzyme-linked immunosorbent assay(ELISA),analysed the difference of serum APE1 between case and control,and the relationship between serum APE1 and NSCLC.Then the correlation between serum APE1 level and the expression of APE1 in tissues was analyzed in 52 NSCLC patients,and the association between serum APE1 level and disease outcomes was investigated in 236 patients who completed at least 6 cycles of standard treatments.In the second part,the sera APE1-AAbs level were dectected in 150 patients with colorectal cancer and 170 heathy control with ELISA,and the CEA,CA199,CA242 were dectected by using protein chip method.Then analysed diagnostic value of APE1-AAbs with ROC curve and Logistic regression.ResultsThe serum APE1 level of patients with NSCLC was significantly higher than that of the healthy control(0.161 vs.0.098ng/ml,p< 0.001).Serum APE1 is an independent predict factor for NSCLC(OR: 6.082).Serum APE1 level was correlated with the expression of APE1 in tissues(r2= 0.639,p< 0.001).High serum APE1 before treatment was associated with poor disease control rate(OR:2.600,p= 0.002).Patients with low serum APE1 level before treatment had better progression free survival(10.0 vs.6.0 months,p= 0.001).The progression free survival and overall survival of patients with low serum APE1 were significantly better than that of patients with high serum APE1 after the treatment(12.0 vs.4.0months,p< 0.001;32.0 vs.18.0months,p= 0.016).In part 2,the level of serum APE1-AAbs in colorectal cancer patients was significantly higher than that of healthy controls(2.697 vs.1.920,p< 0.001).The area under the receiver operating characteristic curve was 0.797,the sensitivity was 62.67%,while the specificity was 85.29%.With the combination of APE1-AAbs and CEA,CA242,CA199,all the AUC of ROC,sensitivity and accuracy for diagnositic colorectal cancer were increased.ConclusionsSerum APE1 protein can be used as a biomarker for diagnosis NSCLC and predicting the efficacy of platinum therapy and prognosis.The chemotherapy-na?ve serum APE1 level and the change trend of APE1 after treatment was closely associated with the outcome of NSCLC patients receiving platinum therapy.The serum APE1-AAbs is valuable for diagnosis of colorectal cancer,combined detection of APE1-AAbs with other tumor markers such as CEA,can improve the sensitivity and accuracy of the diagnosis of colorectal cancer.