LINC00261 regulates EBF1 to suppress malignant progression of thyroid cancer.

OBJECTIVE: We aimed to explore the role of LINC00261 in thyroid cancer (TC) and the potential regulatory mechanism. PATIENTS AND METHODS: 40 cases of tumor tissues and adjacent tissues of TC patients were collected, and the expressions of LINC00261 and EBF1 were detected by quantitative real-time polymerase chain reaction (qRT-PCR), and the relationship between LINC00261 and the clinical pathological indicators and prognosis of TC patients were analyzed. Next, LINC00261 overexpression and knockdown cell models were constructed in TC cell lines BPH5-16 and K1, respectively. Cell counting kit-8 (CCK-8) and transwell migration were used to detect the impact of LINC00261 overexpression or silencing on cell proliferative and migration ability. The bioinformatics website was used to screen the possible target gene of LINC00261. RESULTS: qRT-PCR analysis showed that LINC00261 level was markedly reduced in TC tumor tissues, as well as corresponding cell lines. Retrospective analysis showed that low expression of LINC00261 was in positive correlation with the pathological stage, lymphatic and distant metastasis in patients with TC, meanwhile, the expression of LINC00261 was also in positive correlation with overall survival rate of TC patients. Bioinformatics analysis suggested that LINC00261 could target EBF1. Luciferase reporter gene experiment and qRT-PCR analysis suggested that LINC00261 could target EBF1 and that their expressions showed a negative correlation in TC tumor tissues and cells. Cell functional experiments confirmed that LINC00261 can inhibit the proliferative and migration ability of TC cells. Subsequently, the recovery experiment also suggested that silencing EBF1 could reverse the promotion effect of LINC00261 knockdown on the proliferative and migration ability of TC cells; while EBF1 overexpression could reverse the inhibition of LINC00261 on the proliferative and migration ability of TC cells. CONCLUSIONS: LINC00261 was markedly downregulated in TC tissues and cells. In addition, the level of LINC00261 was closely related to lymph node and distant metastasis, as well as the prognosis in TC patients. Moreover, LINC00261 could negatively regulate EBF1, thereby promoting the malignant progression of TC.