THE RELATION BETWEEN microRNA 221, 222, 146b ve p27Kip1 PROTEIN mRNA SECRETIONS AND CLINICOPATHOLOGICAL PARAMETERS IN THYROID CANCERS AND THE ALTERATION OF miRNA SECRETION IN THE PRESENCE OF HASHIMOTO THYROIDITIS

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 459-496-Thyroid Neoplasia & Case Reports
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-464
Fettah Acibucu, Sebila Dokmetas*, Yusuf Tutar, Sahande Elagoz and Fatih Kilicli
Cumhuriyet University, Sivas, Turkey
MicroRNAs (miRNAs) are functional RNA molecules, which are transcripted from RNA genes in genome but they are not translated to proteins. It has been shown in papillary thyroid cancers that miRNA 221, 222 ve 146b are over secreted and p27Kip1 protein levels are suppressed. We investigated the relation between microRNA 221, 222, 146b ve p27Kip1 protein mRNA secretions and clinicopathological parameters in thyroid cancers and and we have also analyzed whether the levels of miRNA secretion alter in the presence of Hashimoto thyroiditis.

We included paraffin tissue blocks of 77 subjects in four groups; 11 with well-differentiated tumours of unknown malignant potential (WDT-UMP), 28 with papillary thyroid cancer with low recurrence risk, 18 with papillary thyroid cancer with moderate-high recurrence risk and 20 with normal thyroid tissue as control.

The levels of miRNA 221, 222, 146b and mRNA secretion of p27Kip1 protein were significantly different among groups. As the risk of recurrence increased we observed that levels of miRNAs secretion had also increased. The highest secretion levels of miRNAs were found in patients with papillary thyroid cancer with moderate-high recurrence risk. Levels of miRNA 146b, miRNA 221 and miRNA 222 secretions were elevated in patients with capsule invasion, vascular invasion or lymph node metastases when compared to patients without them. miRNA 146b and miRNA 221 secretions were significantly higher in patients with distant metastases.

A positive correlation was found between the tumor size and the levels of miRNA secretion. Levels of miRNA 146b, miRNA 221 and miRNA 222 secretions were not related with age and gender. Levels of miRNA 146b, miRNA 221 and miRNA 222 secretions were negatively correlated with p27Kip1 protein mRNA.. Levels of miRNA 221, 222 ve 146b secretions were higher in patients with WDT-UMP compared to patients with normal thyroid tissue, and levels of p27Kip1 protein mRNA secretion were lower. We did not find any significant difference between the HT and not HT patients by means of miRNA secretion. There was not any correlation between thyroidal autoantibody levels and miRNA secretion.

In conclusion, we have shown that elevated levels of miRNAs 221, 222 and 146b secretions are associated with clinical and pathological parameters which increase recurrence risk in thyroid cancer. Recurrence risk and therefore prognosis may be worse in patients with higher levels of miRNAs secretions.

Nothing to Disclose: FA, SD, YT, SE, FK

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