AIM: To investigate the effect of the expression of miR-375 on the proliferation and invasion of choroidal melanoma(CM)MUM-2B cells.

METHODS: MUM-2B cells were cultured and were transfected with miR-375 mimic sequence(mimic group), miR-375 inhibitor sequence(inhibitor group), negative control group and no treatment(blank group). The qRT-PCR, CCK-8, apoptosis and Transwell experiments were used respectively to detect the expression of miR-375, cell proliferation activity, apoptosis, cell migration and invasion.

RESULTS: Compared with the negative control group(1.01±0.10)and the blank group(1.03±0.07), the expression level of miR-375 in the cells of the mimic group(2.65±0.15)was increased, while the expression level of miR-375 in the cells of the inhibitor group(0.28±0.06)was decreased(P<0.05). Compared with the blank group and negative control group, the OD values of the cells in the mimic group at 24, 48, 72, and 96h were decreased(P<0.05), while the OD values of the cells in the inhibitor group at 24, 48, 72, and 96h were increased(P<0.05). Compared with the apoptosis rates in the blank group and negative control group, which were(20.54±4.01)% and(22.80±4.28)%, the apoptosis rate in the mimic group(39.11±3.37)% was increased(P<0.05), while it was decreased in the inhibitor group(10.13±2.17)%(P<0.05). Compared with the blank group and negative control group, the number of migration cell and the number of invasion cell in the mimic group were decreased(P<0.05), while the number of migration cell and the number of invasion cell in the inhibitor group were increased(P<0.05).

CONCLUSIONS: Up-regulating the expression of miR-375 in MUM-2B cells can reduce cell proliferation activity, accelerate cell apoptosis, and inhibit cell migration and invasion, while down-regulating the expression of miR-375 has the opposite effect. It indicates that miR-375 may play the function of tumor suppressor in the course of CM.