Inhibitory effect of decorin on human pterygium fibroblasts in vitro

AIM: To investigate the effect of decorin (DCN) on the proliferation and apoptosis of human pterygium fibroblasts (HPF) in vitro , and to compare the effect of mitomycin C (MMC) in order to search for a new method to prevent the recurrence after pterygium surgery. METHODS: Human pterygium fiborblasts were isolated from the caudomedial part of pterygium tissues in pterygium patients and then cultured in vitro using tissue inoculation method. The cells were treated with DCN and MMC at concentrations of 0.01, 0.1, 1, 5 and 10 mg/L. The morphological alterations of HPF were observed after 24 h, 48 h or 72 h of treatment. MTT method was used to assay the effects of the 2 drugs at different doses after 12 h, 24 h and 48 h on the proliferation of the cells. The expression of proliferating cell nuclear antigen (PCNA) in each group treated with different doses of DCN was detected by the method of immunohistochemistry after 48 h. The cell cycle distribution was determined by flow cytometry analysis. RESULTS: After administration of 10 mg/L DCN or 1 mg/L MMC for 12 h, the proliferation of HPF was significantly inhibited by both drugs in a dose- and time-dependent manner (P<0.05). After treated with 1~10 mg/L DCN for 48 h, the percentage of HPF in G₀/G₁ phase was increased, while the percentage of HPF in G₂/M phase and S phase (G₂/M%+S%) was decreased after treated with 5~10mg/L DCN for 48 h (P<0.05). The late-apoptotic cells were not found in DCN group and MMC group. DCN dose-dependently inhibited the expression of PCNA in HPF (P<0.05). CONCLUSION: Decorin significantly inhibits the proliferation of HPF, and blocks the cells in G₁ phase.