Protein profiling of papillary thyroid carcinoma with and without lymph node metastasis: a proteomic study

Papillary thyroid carcinoma (PTC) is the most common thyroid carcinoma and fortunately the prognosis is generally good. However, lymphatic metastasis of PTC increases mortality and need aggressive therapy. Thus, it is critical to distinguish PTC with lymph node metastasis (LNM) from PTC without LNM, and identification of biomarkers for PTC with LNM is a major research goal. In this study, we conducted a quantitative proteomics analysis to investigate differentially expressed proteins in PTC with LNM and without LNM. Bioinformatics analysis was performed to unveil physiologically relevant information about the altered proteins. We identified 153 proteins that were expressed differentially specific in PTC with LNM, and 85 proteins were differentially expressed only in PTC without LNM. Bioinformatics analysis revealed that extracellular matrix organization, TCA cycle and binding and uptake of ligands by scavenger receptors as the main categories, and these process may contribute to the lymphatic metastasis of PTC. Our study also suggested that ANXA5, ANXA6, ANXA7, S100A9 and S100A11 might be potential biomarkers for PTC with LNM. These results advanced our understanding of molecular mechanisms underpinning PTC with LNM, and may spare PTC patients without LNM from receiving unnecessary aggressive treatment.