Abstract
Dysregulation of the long noncoding RNA GAS5 in human cancer has been identified in recent studies. In this study, we confirmed a negative correlation between the GAS5 expression level and papillary thyroid carcinoma clinicopathologic characteristics, such as the tumor size, lymph node metastasis, the TNM stage and BRAFV600E mutation. The viability and metastasis of papillary thyroid carcinoma cells were detected by CCK-8 and transwell assays, respectively. The results showed that upregulation of GAS5 significantly inhibited papillary thyroid cancer cell growth, migration and invasion in vitro. RNA transcriptome sequencing was performed to explore the underlying targets of GAS5. Through qRT-PCR and Western blot analysis, we found that ectopic expression of GAS5 significantly increased IFI44 and STAT1 levels. Taken together, these findings suggest that GAS5 is a tumor suppressor in papillary thyroid carcinoma, and the action of GAS5 may be mediated through the IFNγ/STAT1 signaling pathway.