iTRAQ-coupled 2D LC/MS-MS analysis of CXCR7-transfected papillary thyroid carcinoma cells: A new insight into CXCR7 regulation of papillary thyroid carcinoma progression and identification of potential biomarkers.

Previous studies have demonstrated that C-X-C chemokine receptor type 7 (CXCR7) regulates papillary thyroid carcinoma (PTC) growth and metastasis; however, the molecular mechanisms underlying this regulation remain unclear. In the present study, the protein expression profiles of the PTC cell line GLAG-66 and GLAG-66 cells stably transfected with CXCR7 cDNA were analyzed and compared using isobaric tag for relative and absolute quantification-coupled two-dimensional liquid chromatography-tandem mass spectrometry. In total, 2,983 proteins were quantified and 130 proteins were identified to be differentially expressed, of which 87 were significantly upregulated and 43 were significantly downregulated. Gene Ontology enrichment analysis revealed that the differentially expressed proteins were primarily enriched in a number of biological processes, including metabolism-related processes, cellular component organization, transport, cellular development process and the immune response. The differentially expressed proteins identified included fibronectin 1, basigin, periplakin and serpin family B member 5, all of which are associated with cellular junctions and cancer progression. In addition, transgelin-2 and AHNAK nucleoprotein 2 were identified as potential novel biomarkers for the prognosis and treatment of PTC.