miR-182 promotes tumor growth and increases chemoresistance of human anaplastic thyroid cancer by targeting tripartite motif 8.

Chemotherapy is one of the most effective forms of cancer treatment and has been used in the treatment of various malignant tumors. We have gained significant insight into the mechanisms of chemoresistance but the details of the molecular mechanisms remain unclear. In the present study, we found that tripartite motif 8 (TRIM8) expression was downregulated in anaplastic thyroid cancer (ATC) tissues and cell lines. This downregulation of TRIM8 was significantly correlated with the upregulation of miR-182 in human ATC tissues. Bioinformatic analysis and luciferase reporter assays identified TRIM8 as a direct target of miR-182 in ATC. A functional assay using an MTT assay and colony formation showed that miR-182 induced cellular growth by repressing TRIM8 expression. Additionally, overexpressed miR-182 contributed to the chemoresistance of ATC cells by the repression of TRIM8 expression. In conclusion, these results demonstrate that miR-182/TRIM8 may be a therapeutic target for the treatment of chemoresistant human thyroid papillary cancer.