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


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'.
Sheu
Sien-Yi
SY
Institute of Pathology and Neuropathology, University Hospital of Essen, University of Duisburg-Essen, Germany.
Vogel
Esther
E
Worm
Karl
K
Grabellus
Florian
F
Schwertheim
Suzan
S
Schmid
Kurt Werner
KW
D000231:Adenocarcinoma, Papillary / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000236:Adenoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D015321:Gene Rearrangement; D006044:Goiter, Nodular / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D006818:Hyalin / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics / Q000378:metabolism; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000378:metabolism / Q000473:pathology; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
D035683:MicroRNAs; D015514:Oncogene Proteins, Fusion; D011505:Protein-Tyrosine Kinases; C093573:ret-PTC fusion oncoproteins, human; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf