Decreased serum exosomal miR‐29a expression and its clinical significance in papillary thyroid carcinoma

Abstract

Background Aberrant levels of circulating microRNAs (miRNAs) are potential biomarkers in papillary thyroid carcinoma (PTC) diagnosis and therapy. The aim of this study was to evaluate serum exosomal miR‐29a expression as a non‐invasive biomarker for PTC diagnosis and prognosis. Methods Quantitative reverse transcription polymerase chain reaction was applied to measure serum exosomal miR‐29a expression levels in blood samples of 119 patients with PTC and 100 control subjects. Results Serum exosomal miR‐29a expression levels were significantly decreased in PTC cases. In addition, receiver operating characteristic (ROC) analysis revealed serum exosomal miR‐29a could well differentiate PTC from normal controls. Moreover, serum exosomal miR‐29a levels increased progressively and significantly 30 days and 90 days after surgery. Furthermore, PTC patients with lower serum exosomal miR‐29a expression had higher risk of recurrence. Decreased serum exosomal miR‐29a expression was significantly associated with worse clinical variables including tumor size, extrathyroidal extension, and TNM stage, as well as shorter survival. Finally, both univariate and multivariate identified serum exosomal miR‐29a as an independent prognostic indicator for overall survival. Conclusion These results demonstrated that serum exosomal miR‐29a might serve as a potential biomarker for PTC diagnosis and prognosis.

Diagnostic and Prognostic Performance of Liquid Biopsy-Derived Exosomal MicroRNAs in Thyroid Cancer Patients: A Systematic Review and Meta-Analysis

“…Finally, the remaining 12 articles, including 1164 patients and 540 controls, met the inclusion criteria ( Figure 1 ). Apart from a single study [ 25 ], all articles were conducted in China [ 21 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. They were published between 2016 and 2021.…”

“…A total of 49 exosomal miRNAs (37 up and 12 down) were significantly deregulated in the circulation of thyroid cancer patients. Pooled meta-analysis of studies showed 16 upregulated miRNAs [ 30 , 32 , 33 , 34 , 35 ] and four downregulated miRNAs [ 26 , 28 , 32 ] in the circulatory exosomes of cancer versus normal subjects. To compare cancer and nodular goiter, 21 upregulated [ 25 , 31 , 32 , 33 ] and 9 downregulated miRNAs [ 31 , 32 ] were observed.…”

“…Considering studies reporting multivariate analysis for predicting survival and lymph node biopsy [ 21 , 28 ], the relative risk and 95% confidence interval for univariate and multivariate analyses are reported in Figure 6 . Lower expression of miR-29a was associated with shorter survival times and nearly 4-fold increased risk of mortality (RR = 3.85, 95%CI = 1.76–6.25, p = 0.010), whereas the upregulated profiles of miR-146b-5p (RR = 1.71, 95%CI = 1.16–2.56, p = 0.012) and miR-222-3p (RR = 1.86, 95%CI = 1.21–2.89, p = 0.002) were independent predictors for lymph node metastasis in thyroid cancer.…”

“…Another miRNA, miR-29a had similar discrimination ability to predict the late stage (AUC = 0.758, 95%CI = 0.70–0.81), which was not significant from miR-485-3p (De Long test: p > 0.05). Lower expression of exosomal miR-29a was also associated with recurrence prediction (AUC = 0.753, 95%CI = 0.68–0.80) [ 28 ].…”

“… Deregulated exosomal miRNAs in thyroid cancer. ( A ) Venn diagram shows the intersection between aberrantly expressed miRNAs across studies with different comparisons [ 25 , 26 , 28 , 30 , 31 , 32 , 33 , 34 , 35 ]. The Venn diagram was plotted online ( ) (accessed on 15 July 2021) [ 36 ].…”