[Effect of miR-204-5p on the proliferation, migration, and invasion on tongue squamous cell carcinoma SCC25 cells by targeting bromodomain-containing protein 4].

Objective: This study aimed to explore the target relationship between miR-204-5p and bromodomain-containing protein (BRD) 4, as well as their effects on cell proliferation, migration, and invasion in tongue squamous cell carcinoma SCC25.

Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to detect miR-204-5p and BRD4 expression levels in tongue squamous cell carcinoma and different cell lines. TargetScan and dual luciferase reporter assay were used to confirm the target relationship between miR-204-5p and BRD4. The effects of miR-204-5p on SCC25 cell proliferation were examined by cell counting kit (CCK) 8 assay, whereas those on SCC25 cell migration and invasion were determined by Transwell assay. RT-qPCR and Western blot were used to detect the effects of miR-204-5p mimics and inhibitors on BRD4 expression. Transwell and CCK8 assays were used to detect the effects of miR-204-5p on proliferation, migration, and invasion through BRD4 regulation.

Results: miR-204-5p was significantly downregulated in the tissues and cells of squamous cell carcinoma, and BRD4 showed the opposite result. The increase in miR-204-5p expression can inhibit the proliferation, migration, and invasion of SCC25 cells. TargetScan and luciferase test confirmed that miR-204-5p and BRD4 had a negative regulatory relationship with BRD4, respectively. Moreover, miR-204-5p mimics can inhibit BRD4 expression, and miR-204-5p inhibitors can promote BRD4 expression upregulation. When miR-204-5p and BRD4 were overexpressed in SCC25 cells, BRD4 can make up for the inhibitory effect of miR-204-5p on SCC25 cells.

Conclusions: miR-204-5p could inhibit proliferation, migration and invasion in tongue squamous cell carcinoma SCC25 cells by targeting BRD4 gene.