Exosomal miR-27a-5p Helps Differentiate Parathyroid Carcinoma From Adenoma and Inhibits Apoptosis in Parathyroid Carcinoma Cells.

The differential diagnosis of parathyroid carcinoma (PC) or parathyroid adenoma (PA) in parathyroid tumors is crucial for their treatment and prognostic outcomes. We have reported previously that exosomal miR-27a-5p is different in PC or PA, although there are no published studies on a large number of samples, with the role of miR-27a-5p in regulating the effects of PC progression remaining unknown. The current study was designed to investigate the differential expression pattern of exosomal miR-27a-5p in both PC and PA and its relationship with clinicopathologic features, with the aim of further investigating the effect of PC at the cellular level. The miRNA profiles of serum exosomes from 9 PC and 9 PA patients were evaluated using high-throughput sequencing. The differential expression of exosomal miR-27a-5p was detected in 29 PC and 36 PA patients. We also evaluated the diagnostic efficacy of exosomal miR-27a-5p to identify PC or PA and examined its correlation with the clinicopathologic features of PC. Primary PC cells were obtained by primary cell culture, while the effect of exosomes on PC cell apoptosis was investigated using miR-27a-5p mimic transfection and exosome mixed culture. Finally, the possible target gene of miR-27a-5p, PIK3CA, was identified using a dual-luciferase assay. Exosomal miR-27a-5p differed significantly in PC and PA and was upregulated in PC with good diagnostic efficacy. Exosomal miR-27a-5p was also associated with T-staging of PC. miR-27a-5p inhibited PC cell apoptosis, an action that may be related to its target gene PIK3CA. However, the specific mechanism of this inhibition requires further exploration. The exosomal miR-27a-5p assay is a noninvasive liquid biopsy method that provides an important reference for the timely and accurate identification and treatment of PC. Studies to reveal the mechanism of miR-27a-5p regulation in PC progression are of great significance to improve the current prognostic status of the tumor.