OBJECTIVE: Alterations in microRNA (miRNA) expression have been described in 
thyroid tumors, suggesting a role for miRNAs in thyroid carcinogenesis. 
BRAF(V600E) is the most frequently identified genetic alteration in papillary 
thyroid carcinoma (PTC). We investigated the link between BRAF(V600E) status and 
the expression of miRNAs in PTC and analyzed the associations of these factors 
with clinicopathological characteristics.
DESIGN AND METHODS: Prospective study of patients who underwent thyroid surgery 
between October 8, 2008 and November 1, 2010. BRAF(V600E) status was determined 
by mutant allele-specific amplification PCR and direct sequencing of exon 15 of 
the BRAF gene in 69 PTC tissues and 69 respective paracancerous normal thyroid 
tissues. Initially, miRNA expression was analyzed in 12 PTC tissues and three 
associated paracancerous tissues using a miRNA microarray. miRNAs differentially 
expressed between BRAF(V600E)-positive and -negative PTC tissues were then 
validated by real-time quantitative PCR on 69 PTC tissues and 69 paracancerous 
tissues. We also explored the associations between BRAF(V600E) status or 
differential miRNA expression and clinicopathological characteristics.
RESULTS: The mutation rate of BRAF(V600E) in PTC was 47.8%. Twelve miRNAs were 
upregulated and six were downregulated in PTC tissues, among which miR-15a, 
15a*, 34a*, 34b*, 551b, 873, 876-3p, and 1274a were first identified. miR-21* 
and 203 were significantly dysregulated (P<0.05) in PTC tissues with 
BRAF(V600E). Additionally, there were significant associations (P<0.05) between 
BRAF(V600E) and a higher tumor-node-metastasis staging (III/IV), and between 
miR-21* over-expression and lymph node metastasis.
CONCLUSIONS: We identified two miRNAs that are differentially expressed in PTC 
tissues with BRAF(V600E) and revealed their associations with 
clinicopathological features. These findings may lead to the development of a 
potential diagnostic biomarker or prognostic indicator of PTC.