Apoptosis in Lovo Cells Induced by SFPS was Associated with a Activation of Caspase-3 Mediated by Caspase-9

Abstract: Human colorectal cancer (lovo) cells were chosen to study the anti-tumor effects of Sargassum fusiforme polysaccharides (SFPS) and explore the significance of caspase-3， caspase-8 and caspase-9 in the apoptosis of lovo cells induced by SFPS. Inhibition of the cell proliferation was measured by MTT assay. SFPS induced apoptosis of lovo cells was observed by electron microscopy， flow cytometry and DNA electrophoresis. And the expressions of caspase-3 mRNA and pro-caspase-3， caspase-9 were tested by RT-PCR and Western blot. Furthermore， caspase-3， caspase-8， caspase-9 protease activity was measured by colorimetric assay kit. The results suggested that SFPS exhibited obvious anti-proliferative activity. Morphological examination， DNA ladders and flow cytometry analysis obviously showed cell apoptosis with characteristic morphological changes and DNA fragmentation. Furthermore， the expression of pro-caspase-3 decreased and the level of caspase-3 mRNA increased with the time and dose-dependent manner. However， Western analysis also showed the cleavage of caspase-9， an initiator caspase in SFPS-treated cells. Otherwise， caspase activity assay suggested that SFPS could induce cell apoptosis， which was closely accompanied with increase caspase-3 and caspase-9 activation. In conclusion， our study suggested that SFPS could induce the apoptosis of lovo cells in vitro resulting in the inhibition of proliferation and SFPS-induced apoptosis was associated with activation of caspase-3 mediated by cleavage of caspase-9.
    

CSTR: 32200.14.cjcb.2006.02.0016