AIM: To investigate the expression of protease-activated receptor 2(PAR2)in uveal melanoma(UM), and the effects of silencing the expression of PAR2 gene on proliferation and invasion of human UM cell line M23.

METHODS: A total of 45 patients(45 eyes)with UM who underwent surgical treatment with complete information in our hospital were selected from February 2012 to December 2017. In the same period, 30 patients(30 eyes)who underwent eyeball removal due to ocular trauma and most of the uvea were normal were selected. Real-time quantitative PCR was used to detect the expressions of PAR2 gene in UM and normal choroidal tissues. M23 cells were cultured and divided into PAR2 interference group, negative control sequence group and blank group. Real-time quantitative PCR was used to detect the expression of PAR2 gene in cells. MTT assay was used to detect cell proliferation, and transwell assay was used to detect cell migration and invasion.

RESULTS: The relative expression level of PAR2 mRNA was 1.73±0.13 in UM tissues, and 1.06±0.10 in normal choroid tissues(t=23.732, P<0.001). The relative expression level of PAR2 mRNA in UM tissues was associated with pathological type, scleral invasion, optic disc involvement and extraocular growth(P<0.05). The relative expression level of PAR2 mRNA in PAR2 interference group was lower than that in negative control sequence group and blank group(P<0.05). The absorbance A values at 24h, 48h, 72h and 96h in the PAR2 interference group cells were lower than those in negative control sequence group and blank group(P<0.05). The number of migrated cells and the number of invasive cells in PAR2 interference group were lower than those in negative control sequence group and blank group(P<0.05).

CONCLUSION: PAR2 was highly expressed in UM tissues and was associated with high risk of tumor metastasis. Specific silencing of PAR2 gene expression in M23 cells could effectively inhibit cell proliferation, migration and invasion.