LncRNA Taurine-Upregulated Gene 1 Promotes Cell Proliferation by Inhibiting MicroRNA-9 in MCF-7 Cells.

PURPOSE

This study was designed to investigate the role of taurine-upregulated gene 1 () in MCF-7 breast cancer cells and the molecular mechanism involved in the regulation of microRNA-9 (miR-9).

METHODS

The expression of in breast cancer tissues and cells was evaluated using quantitative reverse transcription polymerase chain reaction. Cell viability was examined using a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay; cell cycle progression and apoptosis were analyzed using flow cytometry. A dual luciferase reporter assay was used to detect the relationship between and miR-9. The expression of methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) was measured by western blot.

RESULTS

Higher expression of was observed in breast cancer tissues and cell lines than in the corresponding controls. knockdown reduced proliferation, suppressed cell cycle progression, and promoted apoptosis of MCF-7 cells. The dual luciferase reporter assay showed that could negatively regulate the expression of miR-9. MiR-9 inhibition abrogated the effect of knockdown on the proliferation, cell cycle progression, and apoptosis of MCF-7 cells. positively regulated the expression of MTHFD2 in breast cancer cells.

CONCLUSION

knockdown was significantly associated with decreased cell proliferation and it promoted apoptosis of breast cancer cells through the regulation of miR-9.