miR-21-3p regulates keratinocyte proliferation and apoptosis possibly via regulating Janus kinase/signal transducer and activator of transcription-3 pathway and cytokeratin 17 expression.

Objectives: We investigated the effect and mechanism of miR-21-3p on the biological behavior of keratinocyte HaCaT cells. Methods: HaCaT cells were transfected with miR-21-3p mimics and miR-21-3p inhibitor, respectively. Cell proliferation was detected by CCK-8, and apoptosis and cell cycle were analyzed by flow cytometry. The expression changes of Bax and Bcl-2 were measured with immunohistochemistry. The mRNA expressions of IL-17A and STAT3 were detected by real-time fluorescence quantitative PCR. Cytokeratin 17 protein was detected by Western blot. The relationship between miR-21-3p and STAT3 was verified by dual luciferase reporter gene assay. Results: The miR-21-3p mimics significantly promoted the proliferation and cell cycle progression of HaCaT cells. However, miR-21-3p mimics significantly inhibited cell apoptosis, decreased Bax expression and increased Bcl-2 expression. Additionally, miR-21-3p mimics significantly increased the expressions of Cytokeratin 17 protein, IL-17A mRNA and STAT3 mRNA. Of note, the miR-21-3p inhibitor exhibited contrary effects to miR-21-3p mimics. Furthermore, STAT3 was a direct target of miR-21-3p. Conclusion: miR-21-3p may promote the abnormal proliferation and inhibit apoptosis of HaCaT cells, possibly through regulating JAK/STAT pathway and the expression of Cytokeratin 17. [ABSTRACT FROM AUTHOR]