Background: Cervical lymph node metastasis is an important prognostic indicator for papillary thyroid carcinoma (PTC) and affects treatment strategies for PTC. lncRNAs essentially contribute to the biological functions of tumors. This study aimed to identify the lncRNAs associated with cervical lymph node metastasis and prognosis of PTC and their potential pathophysiological mechanisms.
Materials and methods: PTC-associated lncRNAs were selected from The Cancer Genome Atlas database, and correlations among lncRNAs, lymph node metastasis, tumor staging, and prognosis of PTC were analyzed in silico. These correlations were then validated through quantitative reverse transcription PCR (qRT-PCR) and immunohistochemistry (IHC).
Results: In silico analysis showed that FAM95B1  and UCA1  were significantly correlated with cervical lymph node metastasis, tumor staging, and PTC prognosis (P <0.05). qRT-PCR analysis revealed high UCA1 expression in PTC tissues and correlations between UCA1 expression levels and cervical lymph node metastasis and tumor staging in PTC, that is, higher UCA1  expression resulted in poorer PTC prognosis. IHC analysis revealed that a high expression of UCA1  was accompanied by a high expression of metastasis-related proteins (MMP-2 and MMP-9), thereby validating the correlation of UCA1  expression with metastasis.
Conclusion: FAM95B1  and UCA1  expression was significantly correlated with the occurrence and progression of PTC. The expression levels of UCA1  significantly affected the prognosis of PTC patients and were significantly correlated with tumor staging and cervical lymph node metastasis.
Keywords: papillary thyroid carcinoma, lncRNA, FAM95B1 , UCA1