Apoptosis of human colon carcinoma HT-29 cells induced by ceramide

AIM: To investigate the effect of exogenous ceramide-induced apoptosis on human colon carcinoma HT-29 cells. METHODS: Light microscope, transmission electron microscope and fluorescence microscope were used to observe the morphology change of apoptosis in HT-29 cells. Agarose gel electrophoresis was performed to detect the DNA fragment. Mitochondrial function was detected by MTT assay. mRNA expression of Bcl-2 family gene members was determined by reverse transcription polymerase chain reaction (RT-PCR) assay. RESULTS: After C-2-ceramide treatment, typical characteristics of apoptosis, such as nuclear chromatin breakage, apoptotic body and DNA ladder, could be observed. After exposure to 50 mu mol/L C-2-ceramide for 12 and 24 h, cell apoptosis was 64.1% and 81.3% respectively, which had a time-and dose-effect relationship. Mitochondrial function started to decrease from 6 h after exposure to ceramide. Meanwhile, ceramide up-regulated or down-regulated the mRNA expression of Bcl-2 family gene members. CONCLUSION: Ceramide induces apoptosis of human colon carcinoma HT-29 cells by affecting the expression of Bcl-2 family gene members and impacting the mitochondrial function. (C) 2006 The WJG Press. All rights reserved.