Background: LncRNAs play important roles in papillary thyroid carcinoma (PTC). LINC02471  has been reported to be related to PTC prognosis. The current study aimed to investigate the effects of LINC02471  on human PTC cells.
Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to examine LINC02471  expression in PTC tissues and cells and miR-375 expression in PTC cells. SiLINC02471 , miR-375 mimic and miR-375 inhibitor were used for cell transfection. Cell proliferation, apoptosis, migration, and invasion were detected by performing Cell Counting Kit-8 (CCK-8), clone formation assay, flow cytometry, scratch assay, and transwell assay. Western blot was carried out to detect protein levels of E-cadherin, N-cadherin and Snail. The target gene for LINC02471  was verified by dual-luciferase reporter assay.
Results: LINC02471 was highly expressed in PTC tissues and cells. After silencing LINC02471 , cell proliferation, migration and invasion were reduced, but cell apoptosis was increased. SiLINC02471  increased the expressions of E-cadherin and miR-375, and inhibited the expressions of N-Cadherin and Snail. LINC02471  directly targeted miR-375 in PTC cells. Overexpression of miR-375 inhibited the proliferation, migration, invasion of PTC cells and reduced the expressions of N-Cadherin and Snail but promoted the cell apoptosis and increased E-cadherin expression, while miR-375 inhibitor produced opposite effects to overexpressed miR-375. After inhibiting miR-375 expression, siLINC02471  reversed the effect of miR-375 inhibitor.
Conclusion: LINC02471 could promote the development of PTC. Knocking down LINC02471  could inhibit invasion and metastasis and promote PTC cell apoptosis through directly targeting miR-375.
Keywords: papillary thyroid carcinoma, long non-coding RNAs, miR-375, epithelial-mesenchymal transition, EMT