Potential Evaluation of SULT1A3 as an Early Diagnostic Marker for Nasopharyngeal Carcinoma: A Study Based on Plasma Proteomics Screening and ELISA Validation

(1) Background: Nasopharyngeal carcinoma (NPC) is a highly prevalent and aggressive malignancy in Southeast Asia, and early diagnosis is pivotal for reducing mortality; however, the lack of early specific biomarkers remains a major clinical bottleneck; (2) Methods: We conducted a plasma proteomic analysis using mass spectrometry on 15 untreated early stage NPC patients and 15 healthy individuals positive for VCA-IgA antibodies, followed by bioinformatics analysis to identify differentially expressed proteins (DEPs) and ELISA Validation; (3) Results: Proteomic analysis identified 1,428 serum proteins, with 1,410 quantifiable. The analysis identified 31 upregulated and 189 downregulated proteins, with the key upregulated proteins being LTA4H, SULT1A3, and FGL1. LTA4H with plasma cells (0.38305252), CD8 T cells (0.407959118), SULT1A3 with M1 macrophages (0.509905899), and FGL1 with M1 macrophages (0.430029014). These findings indicate specific relationships between the upregulated proteins LTA4H, SULT1A3, FGL1 and certain immune cell types/proportions verified by ELISA experiments.The ELISA validation results demonstrated: LTA4H AUC=0.631, SULT1A3 AUC=0.787, and FGL1 AUC=0.688 (n=80). SULT1A3 AUC=0.826 (cohort 1, n=196),SULT1A3 AUC=0.793 (cohort 2, n=112); (4) Conclusions: By integrating a machine learning-based method with deep proteomic analysis, we explored the pathological mechanisms and identified biomarkers for NPC. We validated the effectiveness of SULT1A3 as a potential biomarker for nasopharyngeal carcinoma through ELISA, which contributes to the development of more effective diagnostic strategies and may pave the way for further research on targeted therapies.