Hyalinizing trabecular tumour of the thyroid-differential expression of distinct miRNAs compared with papillary thyroid carcinoma

作者：Sheu Sien Yi; Vogel Esther; Worm Karl; Grabellus Florian; Schwertheim Suzan; Schmid Kurt Werner^*

来源：Histopathology, 2010, 56(5): 632-640.

DOI：10.1111/j.1365-2559.2010.03526.x

• hyalinizing trabecular tumour
• miRNA
• papillary thyroid carcinoma
• thyroid

Hyalinizing trabecular tumour of the thyroid-differential expression of distinct miRNAs compared with papillary thyroid carcinoma
Aims:
To compare the expression pattern of five microRNAs (miRNAs) (146b, -181b, -21, -221, -222) of papillary thyroid carcinoma (PTC) and hyalinizing trabecular tumour of the thyroid (HTT).
Methods and results:
The expression pattern of five miRNAs known to be up-regulated in PTC was retrospectively analysed in 18 HTTs, adjacent normal thyroid tissue, 10 PTCs, 10 follicular adenomas and 10 non-toxic multinodular goitres (MNG) by reverse transcriptase-polymerase chain reaction using the TaqMan miRNA assay. Furthermore, the two common genetic alterations characteristic for PTC, the V600E mutation of the BRAF gene and RET/PTC 1 and 3 rearrangements, were determined in all HTTs. All miRNAs were significantly up-regulated in PTCs, whereas all miRNAs in HTT, normal thyroid tissue, adenomas, and MNGs were down-regulated. Calculating relative changes in gene expression, a 510-fold change of miRNA 146b between PTC and HTT could be observed followed by fold changes between 6.4 and 29 in the remaining miRNAs (P < 0.001). All HTTs lacked BRAF mutations and RET/PTC rearrangements.
Conclusions:
Our findings do not support the concept that a high proportion of HTT represents a variant of PTC. It is suggested that HTTs lacking both a miRNA expression pattern characteristic for PTC and RET/PTC rearrangements are re-designated as 'hyalinizing trabecular adenomas'.

• 出版日期2010-4