Cycloprodigiosin hydrochloride, a H+/Cl- symporter, induces apoptosis in human colon cancer cell lines in vitro.

Recently, we reported that cycloprodigiosin hydrochloride (cPrG.HCl), a novel H+/Cl- symporter, induces acidification of the cytosol and leads to apoptosis on rat and human liver cancer cells. In the present study, the effects of cPrG.HCl, a H+/Cl- symporter, were examined in colon cancer cell lines in vitro. In the MTT assay, cPrG.HCl inhibited the growth of two colon cancer cell lines (WiDr and SW480) in a dose- and time-dependent manner. The cPrG.HCl treatment of both types of cells induced apoptosis as confirmed by the appearance of a sub-G1 population and intranucleosomal DNA fragmentation. In addition, cPrG.HCl lowered pHi (below pH 6.8) respectively. Therefore, these results suggest that cPrG.HCl may be useful for the treatment of colon cancer cells.