Effect of AATI, a Bowman-Birk type inhibitor from Apios americana, on proliferation of cancer cell lines

In this paper, the inhibitory effects of AATI on proliferation of four cancer cell lines were investigated. Compared with SBBI, AATI showed the same or stronger inhibitory effect on the proliferation rate among the cell lines tested. The morphology of the cell treated with AATI appeared irregular and the adhesion ability was changed among cells. The nuclei of the cells presented characters of apoptosis. Furthermore, the amount of phosphatidylserine in the outer leaflet of the cell membrane was increased significantly during the treatment. The genomic DNA test suggested that inhibitory effects on the proliferation of cells by AATI was caused by induction of apoptosis. Moreover, chemical modification of arginine or lysine residues in AATI resulted not only in the partial loses of protease-inhibitory activity, but also in the inhibitory effect on cancer cell lines, suggesting that the inhibitory effects on the proliferation are strongly correlated with its protease-inhibitory activity.