The lncRNA UNC5B-AS1 promotes proliferation, migration, and invasion in papillary thyroid cancer cell lines.

The incidence of thyroid cancer detection is continually improving worldwide with the spread of diagnostic imaging and surveillance. Although we have made great progress, there are still unknown mechanisms of papillary thyroid cancer. We found that UNC5B-AS1 is a potential oncogene in thyroid cancer. Therefore, our study aimed to investigate the biological functions of the lncRNA UNC5B-AS1 in papillary thyroid cancer. As a result, RNA-seq data on primary papillary thyroid cancer (PTC) in the TCGA database were obtained. RT-qPCR was performed to evaluate the expression levels in thyroid tissue. We then analysed the expression level of UNC5B-AS1 and its association with clinicopathologic characteristics in the TCGA database. We downregulated UNC5B-AS1 using small interfering RNA and carried out assays of cell proliferation, colony formation, migration and invasion to explore the function of UNC5B-AS1 in PTC cell lines (TPC1 and BCPAP). These results suggested that the lncRNA UNC5B-AS1 was significantly upregulated in both the TCGA cohort and our tissue cohort. Upregulated UNC5B-AS1 correlated with lymph node metastasis (P < 0.001), tumor size (P = 0.002) and histological type (P = 0.013). We also achieved an area under the ROC curve (AUC) of 93.2% for our validated cohort, which was consistent with the AUC of 94.5% for the TCGA cohort, for differentiating between PTC tissues and normal tissues. Downregulating UNC5B-AS1 expression at the RNA level significantly inhibited cell proliferation, colony formation, migration, and invasion in PTC cell lines (TPC1 and BCPAP). This study demonstrated that the lncRNA UNC5B-AS1 plays an important role in tumourigenesis and metastasis of PTC and may be a potential therapeutic target for PTC.