Expression profiling and bioinformatics analysis of serum exosomal circular RNAs in lymph node metastasis of papillary thyroid carcinoma

Most papillary thyroid carcinoma (PTC) patients have a good prognosis, but lymph node metastasis (LNM) is the most common progressive manifestation and often leads to a poor-prognosis. However, few studies focused on the underlying mechanisms of LNM. This study aimed to identity the potential role of exosomal circRNAs that contribute to LNM in PTC. We found that 9000 aberrantly expressed exosomal circRNAs in PTC patients with LNM, including 684 observably upregulation and 2193 notably downregulation. Functional enrichment analyses indicated that these aberrantly expressed circRNAs were mainly enriched in a variety of molecules and signaling pathways related to the progression and LNM of PTC. Bioinformatics analysis screened 14 circRNA-miRNA-mRNA networks associated with LNM-related signaling pathways in PTC. Moreover, circTACC2-miR-7-EGFR and circBIRC6-miR-24-3p-BCL2L11 axes were verified for potential involvement in PTC with LNM. Additionally, 4 upregulated circRNAs-related hub genes and 8 hub genes associated with downregulated circRNAs were screened, some of which were involved in LNM of PTC through verification. Collectively, our data provided a novel framework for in-depth investigation of the function of dysregulated exosomal circRNAs and their potential biomarkers in PTC patients with LNM.