Page 25 - SDIR5 Abstract book 21 12 2021.

CANCER AND METABOLISM

Hsa-miR-222 identifies high-risk PTC patients with classical variant architecture

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Stefana Stojanović , Sonja Šelemetjev , Ilona Đorić , Jelena Janković Miljuš , Vladan Živaljević , Svetislav
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Tatić , Tijana Išić Denčić
1 Institute for the Application of Nuclear Energy — INEP, University of Belgrade, Belgrade, Serbia
2 Center for Endocrine Surgery, Institute of Endocrinology, Diabetes and Diseases of Metabolism, Clinical Center of
Serbia, Belgrade, Serbia
3 Institute of Pathology, Medical Faculty, University of Belgrade, Belgrade, Serbia

Background: Finding novel tumor markers useful to recognize high-risk thyroid carcinoma patients is of
great importance. We evaluated hsa-microRNA-222 (miR-222) for differential diagnosis of thyroid
neoplastic lesions and assessed its prognostic usefulness. Material and Methods: MiR-222 levels were
determined in 77 cases of papillary thyroid carcinomas (PTC) of diverse histological variants, 12 cases of
follicular thyroid adenoma (FTA), and 99 matched nonmalignant thyroid epithelial tissues (NMT) using RT-
qPCR. The results were evaluated in comparison with clinicopathological features of PTC. Results: Relative
miR-222 expression is higher in PTC than in FTA and NMT (p<0.05). Compared to the levels in paired NMT,
miR-222 is up-regulated in PTC, while being down-regulated in FTA (median 2.22 [0.71–8.81] vs. 0.40 [0.09–
2.07], p<0.05). Althought increased expression of miR-222 could be used as sensitive (76.6%) and specific
(75.0%) marker for discriminating PTC from FTA (cut off=0.66, AUC=0.747, p<0.01), miR-222 expression
depends on PTC subtype. Only PTCs with areas of classical variant architecture tend to have high values of
miR-222 relative expression, while folicular variant of PTC and selected rare PTC variants (Warthin-like, tall
cell, solid, clear cell, oxyphilic) tend to have lower values (p<0.05). Higher miR-222 expression in PTC
associate with the presence of metastasis in the regional lymph nodes, the presence of extrathyroidal
invasion, degree of tumor infiltration through the gland, higher pT and pTNM stage (p<0.05). Conclusions:
MiR-222 is a useful marker for PTC detection, particularly its classical variant, and can help in risk
stratification of these patients.
Keywords: Diagnosis, Micro RNA, Papillary Thyroid Carcinoma, Prognosis, Tumor Marker

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