TF/FVIIa/PAR2 promotes cell proliferation and migration via PKCα and ERK-dependent c-Jun/AP-1 pathway in colon cancer cell line SW620

Our previous study has demonstrated that tissue factor-factor VIIa (TF/FVIIa) complex promotes the proliferation and migration of colon cancer cell line SW620 through the activation of protease-activated receptor 2 (PAR2). In the current study, the underlying molecular mechanisms of TF/FVIIa/PAR2 signaling in SW620 cells were further explored, with the focus on the role of activator protein-1 (AP-1) subunit c-Jun. The results revealed that PAR2-AP and FVIIa could upregulate c-Jun expression and c-Jun phosphorylation in SW620 cells in a time-dependent manner. The effect of FVIIa was significantly blocked by anti-TF and anti-PAR2 antibodies. Protein kinase C alpha (PKC alpha) inhibitor safingol and extracellular signal-regulated kinase 1 and 2 (ERK1/2) inhibitor U0126 abrogated the activation of c-Jun. In contrast, Ca2+ chelators EGTA and thapsigargin, and p38MAPK inhibitor SB203580 had no effect. Suppression of c-Jun/AP-1 activation using a natural inhibitor curcumin decreased the expression of caspase-3, MMP-9, and TF, as well as the proliferation and migration of SW620 cells induced by PAR2-AP or FVIIa. Collectively, our findings suggest that c-Jun/AP-1 activation is required for TF/FVIIa/PAR2-induced SW620 cell proliferation and migration. PKC alpha and ERK1/2 are located upstream of c-Jun/AP-1 in this signaling pathway. Pharmacological inhibition of this pathway might be a novel strategy for colon cancer therapy.