LETTER TO THE EDITOR

The prognostic value of miRNA146a in follicular thyroidcarcinoma

Luca Roncati • Manuela Simoni • Antonio Maiorana

Received: 8 August 2013 / Accepted: 20 August 2013 / Published online: 28 August 2013

� Springer Science+Business Media New York 2013

MicroRNAs (miRNAs) are small non-coding RNA mole-

cules of 21–22 nucleotides in length, acting as biological

regulators. They keep the gene expression under control

during the transcriptional and post-transcriptional phases,

resulting in gene silencing via translational repression or

mRNA-target degradation. By affecting gene regulation,

microRNAs are involved in the most important biological

processes, and their expression is deregulated in several

types of human cancers, including thyroid cancer [1]. The

dysregulation of certain microRNAs (oncomiRs) has been

associated with specific oncogenic events (carcinogenesis,

malignant transformation, metastasis). More in particular,

the miRNA146a has been recently found overexpressed in

papillary thyroid carcinoma and in anaplastic thyroid car-

cinoma [2]. For the first time in the literature, we have

evaluated the miRNA146a expression profile by real-time

RT-PCR in 35 formalin-fixed paraffin-embedded samples

of follicular thyroid carcinoma, surgically removed from

35 patients of both sex, aged between 18 and 85 years. The

overall quantity (lg) of miRNA146a was reduced with

statistical significance (p = 0.043) in neoplastic tissue,

compared to healthy thyroid tissue. However, we have

observed an overexpression of miRNA146a in all the 5

cases (14 %) of neoplastic tissue coming from patients

affected by minimally invasive follicular thyroid carci-

noma (Fig. 1), metastatic to other organs, in particular to

the lymph nodes. Our data support that miRNA146a could

play a key role in the regulation of the angiogenic activity

[3] in follicular thyroid carcinoma, promoting, at the same

time, the lympho-vascular invasion (Fig. 1) and the meta-

static evolution of the neoplasia. The overexpression of

miRNA146a may so emerge as a predictor of a poorer

prognosis for different types of malignancies [1–3] and a

potential anti-angiogenic target.

L. Roncati (&) � M. Simoni � A. Maiorana

University of Modena and Reggio Emilia, Modena, Italy

e-mail: emailmedical@gmail.com

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Med Oncol (2013) 30:703

DOI 10.1007/s12032-013-0703-8

Conflict of interest None.

References

1. Wang Z, Zhang H, Zhang P, Li J, Shan Z, Teng W. Upregulation

of miR-2861 and miR-451 expression in papillary thyroid

carcinoma with lymph node metastasis. Med Oncol. 2013;30:577.

2. Pacifico F, Crescenzi E, Mellone S, Iannetti A, Porrino N, Liguoro

D, et al. Nuclear factor-{kappa}B contributes to anaplastic thyroid

carcinomas through up-regulation of miR-146a. Clin Endocrinol

Metab. 2010;95:1421–30.

3. Zhu K, Pan Q, Zhang X, Kong LQ, Fan J, Dai Z, et al. MiR-146a

enhances angiogenic activity of endothelial cells in hepatocellular

carcinoma by promoting PDGFRA expression. Carcinogenesis.

2013;. doi:10.1093/carcin/bgt160.

Fig. 1 Minimally invasive

follicular thyroid carcinoma:

infiltration of the surrounding

fibrous capsule (a, blue arrows,

haematoxylin–eosin, original

magnification 94) and

microvascular invasion (b,

haematoxylin–eosin, original

magnification 910) are

noticeable. The neoplastic cells

are intermingled with

erythrocytes inside the vascular

lumen (b, green arrow)

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