Tissue factor (TF) is believed to play an important role in tissue repair, inflammation, angiogenesis, and tumor metastasis. Protease-activated receptors (PARs) are widely expressed on various cells including tumor cells and associated with many pathological mechanisms. In the present study, the expression of TF and PAR1, PAR2 on human colon cancer cells (SW620 and SW480) was investigated and their functional roles on the behavior of tumor cells were evaluated. It was demonstrated that SW620 and SW480 cells expressed TF at antigen, activity and mRNA levels. However, the highly metastatic cell line SW620 showed slightly higher TF expression than the low metastatic cell line SW480. The PAR2 antigen was strongly expressed on the membrane of SW620 cells, but not on SW480 cells. The PAR1 antigen was not observed in SW620 or SW480 cells, while PAR1 and PAR2 mRNA was detected in SW620 and SW480 cells. The migratory potential of SW620 was stronger than that of SW480 seen in Boyden chambers. PAR2 agonist (SLIGKV-NH2) and factor VIIa significantly stimulated SW620 cell proliferation, migratory activity, and interleukin 8 (IL-8) secretion compared to control. The stimulating effects of factor VIIa could be inhibited by anti-TF and anti-PAR2 but not anti-PAR1 antibodies. In summary, this study demonstrates that TF and PAR2 are strongly expressed on highly metastatic colonic tumor cells and are closely associated with the proliferation and migration of the cells. TF may elucidate its roles in colonic cancer invasion and metastasis via PAR2 pathway.

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