[Effect of ceramide on apoptosis of human colon cancer HT-29 cells].

OBJECTIVE: To investigate the effect of apoptosis and mRNA expression of apoptosis-related genes of human colon cancer HT-29 cells induced by exogenous ceramide. METHODS: After HT-29 cells exposed to C2-ceramide for different time, transmission electron microscope and fluorescence microscope were used to observe the morphology change of cells. DNA agarose gel electrophoresis was applied to detect DNA fragmentation of HT-29 cells. The mRNA expression of apoptosis-related genes was determined by reverse transcription polymerase chain reaction (RT-PCR) analysis. RESULTS: Under the contribution of C2-ceramide, typical apoptosis appearance, such as nuclear chromatin breakage, apoptotic body etc and DNA ladder were observed. Exposing to 50 micromol/L C2-ceramide for 12h and 24h, the rate of apoptotic cells were 64.7% and 81.3% respectively, which appeared time-dose-relation. Meanwhile, ceramide increased the expression of Bax, Bad and Bid mRNA, and decreased the expression of Bcl-2 and Bcl-xl mRNA. CONCLUSION: Ceramide may induce apoptosis of human colon cancer HT-29 cells via up-regulating or down-regulating the expression of apoptosis-related genes.