Expression of tissue factor in choroidal melanoma and its significance

Background It is well known that tissue factor (TF) is expressed in tumor cells and neovascular endothelial cells of tumor.It plays an important role in the formation of new blood vessels as well as the growth and metastasis of tumor.However,whether TF is expressed or not in choroidal melanoma(CM)is unclear.Objective This study is to investigate the expression of TF in a choroidal melanoma cell line and human choroidal melanoma.Methods The expression of TF was studied in the optimal choroidal melanoma-1 (OCM-1) cell line and ten specimens from CM patients using immunhistochemistry.Ten normal eye specimens from donators were used as controls.Results The TF protein was mainly expressed in the cytoplasm.It is over-expressed in OCM-1 cells with positive rate of 85.33±5.47%.Hyper-expression of TF also was found in human choroidal melanoma with a positive rate of 41.60±14.17%.The integrated optical density (IOD) of positive cells in CM was 33853.67±16445.30,and only 5.65±4.26% of positive cells was found in normal human choroidal tissue.The IOD of TF expression in normal human choroidal tissue was 426.43±316.62.Conclusion The overexpression of TF in CM cells may be a new immunotherapy target for CM treatment. Key words: tissue factor; choroidal melanoma; immunohistochemistry