miR-146b is highly expressed in adult papillary thyroid carcinomas with high risk features including extrathyroidal invasion and the BRAF(V600E) mutation.
BACKGROUND
Papillary thyroid carcinoma (PTC) are clinicopathogenetically heterogeneous. Micro-RNAs (miRNAs) are involved in the pathogenesis of diverse human cancers, including PTC. Information regarding associations between clinicopathological features of PTC with the expression of specific miRNAs, however, is sparse. In this study, we compared expression of deregulated miRNAs in PTCs to assess this was associated with selected clinicopathogenetic features.


METHODS
We analyzed the expression levels of three reported deregulated miRNAs (miR-221, miR-222, and miR-146b) using quantitative real-time polymerase chain reaction in 100 cases of PTCs with distinct clinicopathogenetic characteristics and 16 paired normal controls. The tumor samples were categorized into low- and high-risk groups on the basis of the tumor-node-metastasis staging system.


RESULTS
The expression levels of miR-221, miR-222, and miR-146b were significantly associated with extrathyroidal invasion (p = 0.013, 0.05, and 0.003, respectively). The expression levels of miR-221 and miR-146b were significantly higher in the high-risk PTC group (p = 0.01 and 0.042, respectively). The miR-146b expression levels in PTCs with BRAF mutation were significantly higher than those without this mutation (p < 0.0001). There were no other associations between the expression of these miRNAs and other clinicopathological parameters.


CONCLUSIONS
Our results show the potential importance of miR-221, miR-222, and miR-146b in determining the aggressive properties of PTCs and highlight the need to identify the gene targets of these miRNAs.
Chou
Chen-Kai
CK
Division of Metabolism, Department of Internal Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University , Kaohsiung, Taiwan.
Chen
Rong-Fu
RF
Chou
Fong-Fu
FF
Chang
Hsueh-Wen
HW
Chen
Yi-Ju
YJ
Lee
Ya-Fang
YF
Yang
Kuender D
KD
Cheng
Jiin-Tsuey
JT
Huang
Chao-Cheng
CC
Liu
Rue-Tsuan
RT
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000235:genetics* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D009362:Neoplasm Metastasis / Q000235:genetics / Q000473:pathology; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012306:Risk; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology*; D055815:Young Adult
C542542:MIRN146 microRNA, human; D035683:MicroRNAs; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf