MiR-27a-5p inhibits malignant progression of differentiated thyroid cancer by directly affecting the miR-27a-5p/SREBP1 axis.

Abstract

Purpose: To detect the expression of miR-27a-5p in differentiated thyroid cancer (DTC) and to explore its correlation with SREBP1 expression, DTC malignant progression, and TSH suppression therapy.

Methods: The expression levels of SREBP1 and miR-27a-5p in DTC tissues (n = 75) were detected by qRT-PCR. The expression of miR-27a-5p and SREBP1 was statistically analyzed for correlation with patients' postoperative TSH inhibition therapy. Dual luciferase reporter gene assay was performed to verify the target-regulatory relationship between miR-27a-5p and SREBP1. qRT-PCR and Western blots were performed to detect the effect of miR-27a-5p on the expression level of SREBP1. MTS, plate clone formation assay was performed to detect the effect of miR-27a-5p on the proliferative capacity of cells. Flow cytometry was performed to detect the effect of miR-27a-5p on cell cycle and apoptosis. Scratch assay and Transwell assay was performed to detect the effect of miR-27a-5p on cell migration invasion ability.

Results: MiR-27a-5p expression was significantly downregulated in DTC cancer tissues and significantly negatively correlated with SREBP1 expression. It correlated with the outcome of postoperative TSH suppression therapy in DTC patients. The results of dual luciferase reporter gene assay showed that the 3'-UTR region of SREBP1 mRNA was the target site of action of miR-27a-5p. Overexpression of miR-27a-5p was associated with a significant reduction in cell proliferation, cell cycle arrest, increased apoptosis, and diminished cell invasive migration.

Conclusion: The miR-27a-5p expression level was negatively correlated with the progression of DTC, which may be inhibited by targeting SREBP1 and correlated with the outcome of TSH inhibitory therapy.