Inhibition of proliferation and induction of apoptosis in SNU-1 human gastric cancer cells by the plant sulfolipid, sulfoquinovosyldiacylglycerol

The sulfoglycolipid sulfoquinovosyldiacylglycerol is present in the membran es of photosynthetic organisms. This sulfolipid reportedly has pharmaceutic al potential as an antiviral and antitumor agent, although no studies have examined these properties of the sulfolipids that are consumed in plant foo ds. This study examined the biological effects of sulfoquinovosyldiacylglyc erol on the human gastric cancer cell line SNU-1. SNU-1 cells were grown in the absence and of presence of 1 muM, 100 muM or 1 mM sulfoquinovosyldiacy lglycerol for up to 72 hours. Cell proliferation and viability were determi ned. The cells were analyzed for nuclear morphological changes by fluoresce nce microscopy and for DNAase-mediated DNA cleavage by flow cytometry and T UNEL detection. As indicated by cell number, the proliferation of SNU-1 cel ls by 72 hours of culture in the presence of 100 muM and 1 mM SQDG was inhi bited 24 and 100%, respectively, as compared with the number of SNU-1 cells cultured in the absence of SQDG. Inhibition of cell proliferation by 100 m uM sulfoquinovosyldiacylglycerol was in part associated with apoptotic cell death, as shown by changes in nuclear morphology and DNA fragmentation, wh ereas incubation of cells with 1 mM sulfoquinovosyldiacylglycerol caused ne crotic cell death. Treatment of SNU-1 cells with sulfoquinovosyldiacylglyce rol did not result in cell cycle arrest. The antiproliferative and apoptoti c effects of sulfoquinovosyldiacylglycerol on SNU-1 gastric cancer cells re vealed in this study suggest that this common dietary sulfolipid has intrig uing potential as a chemopreventive or chemotherapeutic agent. (C) 2001 Els evier Science Inc. All rights reserved.