[Clinical significance and diagnostic value of Survivin autoantibody in non-small cell lung cancer patients].

BACKGROUND AND OBJECTIVE: Lung cancer is one of the most common cancers worldwide and causes more deaths per year than other cancers. Autoantibody was one hotspot in tumor marker research. But the clinical value of Survivin autoantibody is not clear in lung cancer patients at present. The aim of this study is to determine whether Survivin autoantibody could be used as a diagnostic factor of lung cancer and what the clinical value of Survivin autoantibody was in nonsmall cell lung cancer (NSCLC). METHODS: Survivin cDNA sequence was obtained by RT-PCR and inserted into prokaryotic expression vector pET30a(+). Fusion protein of Survivin was expressed in E. coil BL21(DE3). SDS-PAGE and Western blot were used to confirm the fusion protein. The Survivin protein was purified by Ni-NTA agarose affinity chromatography. At last, indirect ELISA was used to detect Survivin autoantibody level in the serums of 215 samples from NSCLC patients and serums from 20 samples of nonmalignant lung disease patients as well as 89 samples of healthy persons were also detected as control. RESULTS: The recombinant vector pET30a(+)/Survivin was contructed and the Survivin protein is successfully expressed in E.coil BL21(DE3) as inclusion body. Indirect ELISA was done to detect Survivin autoantibody in these serums using purified Survivin protein. It was shown that the positive rate of Survivin autoantibody was 19.5%, with a specificity of 88.9% in NSCLC patients. The expression of Survivin autoantibody has correlation with the volume of tumor and the metastasis of tumor in NSCLC patients (P < 0.05). In our research, positive detection rate of NSCLC was much improved by detecting Survivin autoantibody combined with CEA compared to other tumor markers combined with CEA. CONCLUSIONS: In this study, purified fusion protein of Survivin was successfully obtained. Indirect ELISA for detecting Survivin autoantibody in serum of NSCLC patients using purified Survivin protein was established. Our results indicated that Survivin autoantibody as a latent value of tumor marker could be used for clinical diagnosis in NSCLC patients.