The present study determined the expression of microRNA (miR)-663 in hypertrophic scar (HS) tissues and investigate the regulatory mechanisms of miR-663 in HS. A total of 51 patients diagnosed with HS between December 2013 and February 2016 were included in the present study. HS tissues (experimental group) and HS-adjacent tissues (control group) were collected. Primary fibroblasts were obtained from HS tissue and transfected with small-interfering RNA against transforming growth factor (TGF)-β1 or miR-663 mimics. Reverse-transcription quantitative PCR was used to determine the levels of TGF-β1 mRNA and miR-663. Western blot analysis was performed to determine TGF-β1 protein expression. An MTT assay was employed to detect the proliferation of fibroblasts, and a dual luciferase reporter assay was performed to identify the binding of miR-663 with TGF-β1 mRNA. TGF-β1 was found to have a regulatory role in HS at the transcriptional level. The expression of TGF-β1 was upregulated in HS tissues, and knockdown of TGF-β1 in cultured fibroblasts led to inhibition of proliferation. The expression of miR-663 was downregulated in HS. miR-663 was revealed to regulate the expression of TGF-β1 by binding with the 3'-untranslated region of TGF-β1 mRNA. Elevated expression of miR-663 inhibited the proliferation of fibroblasts by regulating TGF-β1 expression. The present study demonstrated that upregulation of TGF-β1 in HS tissues is associated with the downregulation of miR-663 expression. miR-663 may regulate the proliferation of fibroblasts in HS and the expression of associated proteins.
Keywords: hypertrophic scar; microRNA-663; transforming growth factor-β1.