MicroRNA-21 promotes the proliferation and invasion of cholesteatoma keratinocytes.

Conclusions: The present study revealed that miR-21 promotes the proliferation and invasion of cholesteatoma keratinocytes. These results provide a partial explanation for the more aggressive clinical behavior observed in cholesteatoma.
Objective: This study aims to investigate the post-transcriptional regulatory effects that control proliferation, apoptosis, and invasion in cholesteatoma keratinocytes. In particular, the potential role of miR-21 was focused on in this study.
Methods: Thirty cholesteatoma tissues were processed for RNA and cell culture. Cholesteatoma keratinocytes were transfected with miR-21 mimics, miR-21 inhibitors, or negative control miRNAs; and growth curves were drawn. RT-PCR was used to assess the expression levels of miR-21. EdU incorporation assay and TUNEL staining were used to assess the proliferation and apoptosis of cholesteatoma keratinocytes, respectively. The invasive abilities of cholesteatoma keratinocytes were examined using 6-well Transwell plates.
Results: MiRNA-21 was upregulated when cholesteatoma keratinocytes were transfected with miR-21 mimics. Furthermore, the number of proliferative EdU + cells increased in cholesteatoma keratinocytes transfected with miR-21 mimics; and the number of TUNEL-positive cells also increased in cells transfected with miR-21 mimics. In addition, the number of migrated cells transfected with miR-21 mimics was higher, compared with migrated cells transfected miR-21 inhibitors or control miRNA.