Dysregulation of Pseudouridylation in Small RNAs Contributes to Papillary Thyroid Carcinoma Metastasis

Previous studies have indicated that ψ-modified small RNAs play crucial roles in tumor metastasis. However, the ψ-modified small RNAs during metastasis of PTC are still unclear. We compared the pseudouridine synthase 7 (PUS7) alteration between metastatic and non-metastatic PTCs, and investigated its correlation with clinicopathological features. Additionally, we employed a small RNA ψ modification microarray to examine the small RNA ψ modification profile in both metastatic and non-metastatic PTCs, as well as paired paracancerous tissues. The key molecule involved in ψ modification, pre-miR-8082, was identified and found to regulate the expression of CD47. Experiments in vitro were conducted to further investigate the function of PUS7 and CD47 in PTC. Our results demonstrated that PUS7 was down-regulated in PTC and was closely associated with metastasis. Moreover, the ψ modification of pre-miR-8082 was found to be decreased, resulting in down-expression of pre-miR-8082 and miR-8082, leading to the loss of the inhibitory effect on CD47, thereby promoting tumor migration. Our study demonstrates that PUS7 promotes the inhibition of CD47 and inhibits metastasis of PTC cells by regulating the ψ modification of pre-miR-8082. These results suggest that PUS7 and ψ pre-miR-8082 may serve as potential targets and diagnostic markers for PTC metastasis.