MicroRNA Expression Profiling-Potential Molecular Discrimination of Papillary Thyroid Carcinoma Subtypes

Area of Science:

• Molecular Biology
• Oncology
• Genetics

Background:

• MicroRNAs (miRNAs) play a crucial role in the diagnosis and progression of papillary thyroid cancer (PTC).
• Differentiating between specific PTC subtypes is essential for accurate diagnosis and treatment strategies.

Purpose of the Study:

• To identify a specific miRNA profile capable of differentiating between the infiltrative follicular variant of PTC (iFVPTC) and the conventional variant of PTC (cPTC).

Main Methods:

• A cross-sectional study involving RNA extraction from paraffin-embedded tissues of 43 PTC patients (17 iFVPTC, 26 cPTC).
• Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to evaluate the expression of nine specific miRNAs.

Main Results:

• Distinct miRNA expression patterns were observed between cPTC and iFVPTC.
• Five miRNAs (miR-146b-5p, miR-181a-5p, miR-221-3p, miR-21-5p, miR-222-3p) were altered in both subtypes.
• Two miRNAs (miR-20b-5p, miR-21-5p) were significantly expressed only in cPTC.
• Correlations between miRNA expression and clinical data (age, tumor size, lymph node metastasis) were identified in both groups, with specific miRNAs linked to these parameters in iFVPTC and cPTC.

Conclusions:

• A signature of two miRNAs was identified, confirming molecular differences between the two histological subtypes of PTC.
• These findings represent an advancement in the molecular diagnosis of thyroid cancer.
• The identified miRNA signature could potentially improve the diagnostic accuracy of existing molecular classifiers for PTC.