miR-137 Inhibits Proliferation and Metastasis of Hypertrophic Scar Fibroblasts via Targeting Pleiotrophin.

BACKGROUND/AIMS: There are few effective treatment options for hypertrophic scars. MircoRNAs are a class of small, noncoding RNAs involved in multiple biological functions.

METHODS: Gene chip screening was used to screen out the differential expression of miRNAs in hypertrophic scars and normal tissues. Western blot and real-time PCR were used to confirm the expression of pleiotrophin (PTN) in hypertrophic scars. After analyze the correlation between PTN and miR-137 using correlation analysis, we used miRDB software to analyze the binding sites of miR-137 and PTN. Luciferase reporter gene, western blot and real-time PCR experiments were used to detect the regulatory effect of miR-137 on PTN. MTT and transwell assay were used to detect the effect of miR-137 on proliferation and metastasis. Western blot and real-time PCR were used to detect the regulatory effects of miR-137 on cyclin B1, matrix metalloproteinase 9 (MMP9), α-smooth muscle actin (α-SMA), vimentin, and type-I collagen (COL1A). Finally, miR-137 inhibitor was transfected into fibroblasts which was silent PTN, and the proliferation and migration of cells were detected by MTT and transwell. Western blot and real-time PCR were used to detect the expression of related proteins.

RESULTS: Various miRNAs was abnormal expressed in hypertrophic scars. miR-137 was decreased in hypertrophic scar, however PTN was up regulated in hypertrophic scars. miR-137 induced proliferation and metastasis in fibroblasts. This effect was accompanied by decreased expression of cyclin B1, MMP9, α-SMA, vimentin, and COL1A mediated via the target of PTN.

CONCLUSION: Modulation of miR-137 expression in fibroblasts could provide an important therapeutic strategy for hypertrophic scars.