Exploring Potential Biomarkers of Early Thymoma based on Serum Proteomics

Background: Early diagnosis remains difficult because the early symptoms of thymoma are atypical. Objectives: This study aimed to analyze the changes of serum proteins in the early stage of thymoma (stage I/II) by proteomics method and to screen and validate candidate biomarkers. Methods: Proteins were extracted from 8 sera patients with stage I/II thymoma and 9 healthy controls. The levels of serum proteins were detected by data-independent acquisition (DIA) quantitative proteomics techniques, and the differential proteins were identified. The proteomic results were verified by enzyme-linked immunosorbent assay. Additionally, differentially expressed proteins were analyzed using receiver operating characteristic curves (ROC). Results: There were 80 differentially expressed proteins between the patients with thymoma and the healthy control group, among which 39 were up-regulated and 41 were down-regulated. Differential protein enrichment is involved in environmental information processing, signaling molecules and interactions, and in the body system and the immune system. The analysis of receptor working characteristic curves showed that the areas under the curve of CORO1A, SAA1 and LTA4H were all larger than 0.8, indicating that these proteins had good diagnostic value. Conclusion: CORO1A, SAA1 and LTA4H may be new biomarkers for early screening of thymoma.