RESUMEN
@#[Abstract] Objective: To investigate the effects of long non-coding RNA (lncRNA) taurine up-regulated gene 1 (TUG1) on the proliferation, apoptosis, and epithelial-mesenchymal transition (EMT) of papillary thyroid carcinoma (PTC) cells and its mechanism. Methods: Real-time fluorescent quantitative PCR (qPCR) was used to detect the expression of lncRNA TUG1 in 35 pairs of PTC tissue and corresponding paracancerous tissue specimens that were surgically resected in Tangshan Workers’ Hospital, Hebei Province from May 2019 to April 2021, human PTC cell lines (TPC-1, BHP10-3, K1, SW1736) and human normal thyroid epithelial Nthyori 3-1 cells. TPC-1 cells were cultured in vitro and divided into control group, si-NC group, si-TUG1 group, miR-NC group, miR-524-5p mimic group, si-TUG1+NC inhibitor group, si-TUG1+miR-524-5p inhibitor group, miR-524-5p mimic+pc-DNA group, and miR-524-5p mimic+ pcDNA BRAF (V-raf murine sarcoma viral oncogene homolog B1) group by transfecting corresponding vectors. CCK-8 and FCM methods were used to detect the proliferation and apoptosis of TPC-1 cells, WB method was used to detect the expression of BRAF, proliferating cell nuclear antigen (PCNA), cysteine protease-3 (Caspase-3), E-cadherin, N-cadherin and vimentin in TPC-1 cells, and the dual-luciferase reporter gene experiment was used to verify the targeting relationship between miR-524-5p and lncRNA TUG1 as well as BRAF. Results: lncRNA TUG1 was up-regulated in PTC tissues and cells (P<0.05). Silencing the expression of lncRNA TUG1 or up-regulating the expression of miR-524-5p could significantly inhibit the proliferation and EMT, and promote apoptosis of TPC-1 cells (all P<0.05). Dual-luciferase reporter gene experiment showed that there was a targeting relationship between miR-524-5p and lncRNA TUG1 as well as between miR-524-5p and BRAF (all P<0.05). Silencing the expression of miR-524-5p could reverse the effects of lncRNA TUG1 knockdown on inhibiting proliferation and EMT and promoting apoptosis of TPC-1 cells (all P<0.05), and up-regulation of BRAF expression could reverse the effects of miR-524-5p overexpression on inhibiting proliferation, EMT and promoting apoptosis of TPC-1 cell (all P<0.05). Conclusion: lncRNA TUG1 is up-regulated in PTC tissues and TPC-1 cells. Silencing the expression of lncRNA TUG1 can inhibit proliferation and EMT but promote cell apoptosis of PTC cells by regulating the miR-524-5p/BRAF axis.