FUS-Mediated CircFGFR1 Accelerates the Development of Papillary Thyroid Carcinoma by Stabilizing FGFR1 Protein.

Papillary thyroid carcinoma (PTC) is the most prevalent type of thyroid cancer and its incidence is rising globally. The molecular mechanisms of PTC progression remain unclear, hindering the development of effective treatments. This study focuses on hsa_circ_0008016 (circFGFR1), a circular RNA significantly up-regulated in PTC cells. Silencing circFGFR1 inhibited PTC cell proliferation and increased cell apoptosis, suggesting its role in PTC progression. The RNA-binding protein FUS was identified as a promoter of circFGFR1 formation. While circFGFR1 does not influence FGFR1 mRNA translation, it inhibits ubiquitination and degradation of FGFR1 protein, prolonging its half-life. CircFGFR1 also interacts with protein CBL, inhibiting CBL-mediated ubiquitination of FGFR1 proteins. Rescue assays confirmed circFGFR1 promotes PTC cell growth through mediating FGFR1. This study highlights the potential of circFGFR1 as a therapeutic target, offering insights into PTC's molecular mechanisms, and paving the way for novel treatment strategies.