Fibroblast growth factor 2 (FGF2)regulates signal transduction by forming complexes with its receptors, FGF receptors (FGFRs), and heparan sulfate (HS), playing a crucial role in biological systems. A Show more
Fibroblast growth factor 2 (FGF2)regulates signal transduction by forming complexes with its receptors, FGF receptors (FGFRs), and heparan sulfate (HS), playing a crucial role in biological systems. Although HS has been suggested to modulate FGF/FGFR signaling as a coreceptor, multiple hypotheses exist regarding how HS affects FGF/FGFR signaling and the mechanism remains unclear. Herein, to highlight the role of FGF2/HS interaction in FGF2/FGFR1 signaling, FGF2 mutants with reduced HS-binding affinity are rationally designed through in silico analysis. These FGF2 mutants exhibit reduced HS affinity by more than two orders of magnitude while maintaining binding affinity to FGFR1. In addition, these mutants retain their thermal stability. Cellular assays using the FGF2 mutant suggest that, contrary to previous reports, the contribution of the FGF2/HS interaction in FGF2/FGFR1 signaling may be limited. The mutant FGFs that specifically alter the interaction with HS, achieved in this study, would contribute to an understanding of the role of FGF/HS interaction in FGF/FGFR signaling. Show less
Follicular thyroid carcinoma (FTC) is a common thyroid malignancy that poses diagnostic challenges because of its cytological similarity to benign follicular thyroid adenoma (FTA). The present study a Show more
Follicular thyroid carcinoma (FTC) is a common thyroid malignancy that poses diagnostic challenges because of its cytological similarity to benign follicular thyroid adenoma (FTA). The present study aimed to identify characteristic protein signatures in serum-derived extracellular vesicles (EVs) of FTC and FTA for potential diagnostic and therapeutic applications. Serum EVs from patients with FTC and FTA were purified using the phosphatidylserine affinity method. Proteomics analysis via nano liquid chromatography-tandem mass spectrometry identified 18 significantly differentially expressed proteins between the two patient groups. RAB21, a small GTPase involved in cellular trafficking, was markedly elevated in serum EVs from patients with FTC. Furthermore, cell invasion and migration assays of a human FTC cell line revealed that RAB21 knockdown reduced cell migratory ability, suggesting its role in the malignant phenotype of FTC. The present findings indicated that RAB21 in serum EVs may be a candidate biomarker able to distinguish FTC from FTA, and that RAB21 could be a potential therapeutic target for FTC. Show less