BETA-SITOSTEROL INHIBITS THE GROWTH OF HT-29 HUMAN COLON-CANCER CELLSBY ACTIVATING THE SPHINGOMYELIN CYCLE

The present study examined the SM cycle ns a mechanism to explain the inhibitory effect of SIT on HT-29 cell growth. SIT was the main phytos terol in the diet. Supplementation of SIT at 16 mu M for 5 days in the media inhibited growth by 55% as compared to cholesterol. SIT supplem entation had no effect on sphingosine production. Ceramide production increased 45% with SIT supplementation as compared to cholesterol. Ste rol supplementation had no effect on phospholipase C, a key enzyme in the PKC pathway. We concluded that the activation of the SM cycle may play a role in growth inhibition of HT-29 cells by SIT.