Screening And Identification Of Lung Cancer Associated Antigens Based On SEREX And Oncomine Database

Objective The aim of this study is to screen the tumor-associated antigens(TAAs)of lung cancer and explore the value and significance for diagnosis of lung cancer.Methods1.The lung cancer-associated antigens were screened by the previous SEREX method,then three independent studies(including 375 non-small cell lung cancer and 134 normal tissues)from Oncomine database were used to analyze the m RNA expression of these genes.The differentially expressed genes between lung cancer tissues and normal lung tissues were identified based on the adjusted P value.2.Enzyme linked immunosorbent assay(ELISA)were performed to detect the autoantibodies against TAAs in serum from patients with 184 lung cancer and 184 normal individuals.The autoantibody level between the two groups was compared.Four TAAs showing higher autoantibody level in lung cancer were further selected to be verified in another cohort with lung cancer group(n=446),lung benign disease group(n=119)and normal control group(n=446).3.The OD value that shows the highest sensitivity with more than 90% specificity was taken as cut-off value to calculate the positive frequency of the antibodies in different groups.We assessed the diagnostic value of single autoantibody in detecting lung cancer by the evaluation method of diagnostic test.4.To compare the value of four TAAs with tumor biomarkers for diagnosis of lung cancer.Results1.35 genes whose biological function have been reported were selected from SEREX.m RNA expression of 35 genes in 384 cases of non-small cell lung cancer and 125 normal tissues in three studies were based on Oncomine.Ten genes with differential expression were screened out in three studies.2.The result of ELISA showed that the level and positive frequency of the autoantibodies to TOP2A、ACTR3、RPS6KA5、CD36、PSIP1 and OLA1 were statistically higher in lung cancer patients than that in normal control group in discovery set(P<0.05).The positive frequency of the autoantibodies to PSIP1、TOP2A、ACTR3、RPS6KA5 were statistically higher in lung cancer patients than that in normal control group in validation set(P<0.05).3.The diagnostic sensitivity of a single autoantibody was widely low in discovery set,among3.8%-32.1%.The highest sensitivity was 32.1% for PSIP1 autoantibody.In validation set,the diagnostic sensitivity of this four autoantibodies was among 17.0%-30.5%.This showed that a single autoantibody has a low diagnostic value for lung cancer.The frequency reached at 49.0%when combined detection of these four autoantibodies was used,AUC was 0.701(95%CI:0.670-0.731).4.ROC curve analysis was used to evaluate the diagnostic performance of the four autoantibodies in the lung cancer group,lung benign disease group,and normal control group in the validation set.The results showed that the four autoantibodies can be distinguished the lung cancer group from non-cancer group(lung benign disease group and normal control group)(P<0.05).5.The positive rate of autoantibodies to TOP2 A in early stage lung cancer(36.4%)was significantly higher than that in late stage lung cancer(16.7%)(P<0.05).the positive rate of autoantibodies to ACTR3 in early stage lung cancer(36.4%)was significantly higher than that in late stage lung cancer(15.2%)(P<0.05).the positive rate of autoantibodies to PSIP1 in patients with metastases(30.0%)was significantly higher than that in those without metastases(17.2%)(P<0.05).Whereas there were no statistical relationship with other clinical characters(such as age,gender,smoke,drink,family history of tumor and histological types)(P>0.05).Combinationa ofanti-TOP2A、anti-ACTR3 and protein biomarkers(CA125、CEA and CYFRA 21-1) can improve sensitivity in diagnosis of early stage lung cancer.The positive frequency in early stage lung cancer for each single biomarker was 20.0%,28.6% and 23.5% for CA125,CEA and CYFRA 21-1.When we combined CEA with anti-TOP2 A,the frequency increased to 61.9%.Conclusions1.The autoantibodies against PSIP1,TOP2 A,ACTR3 and RPS6KA5 might be the potential serum biomarkers for lung cancer diagnosis.2.The diagnostic value of single autoantibody was low,combinationa of four TAAs and protein biomarkers can improve sensitivity in diagnosis of early stage lung cancer.3.Autoantibody against TOP2 A and ACTR3 may serve as biomarkers for early diagnosis of lung cancer.4.Combination of TOP2 A,ACTR3 and CA125,CEA,CYFRA21-1 can increase the detection rate in early stage lung cancer.