Study On Novel Serum Biomarkers Of Tumor About Soluble B7-H4 And Protein Masses

Objective Diagnosis of cancer at early stage is important for successful treatment and improving the outcome of patients. To improve its prognosis, we attempted to explore novel tools for screening serum biomarkers. Our object is adenocarcinoma of lung and cancer of esophagus.Methods We used serum samples from 31 adenocarcinoma of lung patients and age, sex and smoking-matched 31 benign individuals. Serum samples were applied to SAX-2 protein chips to generate mass spectra by surface enhanced laser desorption ionization time of flight mass spectrometry(SELDI-TOF-MS). Protein peak identification and clustering were performed using the Biomarker Wizard software and compared their protein masses by the MALTAB7.0 .We used Rweka software to construct a classification tree. The validity of the classification tree was then challenged with a blind test. Meanwhile, we use ELISA kit to analyze the levels of sB7-H4 and CEA in 45 serum samples from patients with cancer of esophagus and 35 samples from healthy controls. We used receiver operating characteristic curve to evaluate the diagnostic value of sB7-H4 and CEA.Results Firstly, the software identified 102 peaks and m/z14022.9和3735.99 were used to construct a classification tree. The classification tree separated adenocarcinoma of lung effectively from benign individuals, achieving a validity of 100%. The blind test challenged the model with a sensitivity of 100% and a specificity of 100%. Secondly, sB7-H4 was present at different levels in all sera and showed a significantly elevated level in serum samples from cancer of esophagus comparing with those from healthy controls. The sensitivity of sB7-H4 is 93% and CEA is 26%.Conclusions: The result suggests that SELDI time-of-flight mass spectrometry technique can correctly distinguish adenocarcinoma of lung patients from benign individuals and shows great potential for the development of a screening test for the detection of lung cancer. On the other hand sB7-H4 is a promising novel diagnostic marker for cancer of esophagus.