Fujimoto et al. BMC Cancer 2010, 10:443 http://www.biomedcentral.com/1471-2407/10/443 Page 6 of 14 Figure 4 Proliferation assay in MKN45/PAR1 with TFLLR-NH2. In the same way, MKN45/PAR1 adding 30 μM TFLLR-NH2 had significantly increased the number, too. And SCH79797 siginificantly reversed the growth rate of MKN45/PAR1 in the presence of 30 μM TFLLR-NH2. (Date were expressed as mean values ± SD from triplicate experiments.) PAR1-transfected MKN45 cells mimic features of PAR1- expressing gastric cancer MKN28 cells To compare MKN45/PAR1 with gastric cancer cells that express endogenous PAR1 mRNA and PAR1 protein, we also performed cell proliferation and invasion assays with MKN28 cells, which express PAR1 (Figure 1A &1B). Upon exposure to a-thrombin, both MKN28 cells and MKN45/PAR1 cells presented an increase in cell proliferation and invasion, and SCH79797 blocked the effects of a-thrombin (Figure 6 &7). Thus, PAR1 in Figure 5 Invasion assay in MKN45/PAR1. Treatment of MKN45/PAR1 with 15 nM a-thrombin or 30 μM TFLLR-NH2 resulted in significant enhancement (5 or 6 fold increment relative to untreated control) of its invasion potential. But treatment of MKN45/mock with same conditions of a-thrombin or TFLLR-NH2 resulted in no significant enhancement. The inhibitory effect of the SCH79797 was clearly observed at 35 and 70 nM. There was the maximum inhibitory effect on the invasion ability of MKN45/PAR1 at 150 nM SCH79797. Basal invading activity was expressed as an absorbance of 560 nm for MKN45/mock cells which were unexposed to a-thrombin. (Date were expressed as mean values ± SD from triplicate experiments.)