The proapoptotic C16-ceramide-dependent pathway requires the death-promoting factor Btf in colon adenocarcinoma cells.
Ceramides are central molecules in sphingolipid metabolism. They are involved in the regulation of cancer-cell growth, differentiation, senescence and apoptosis. To better understand how these secondary messengers induce their biological effects, adenocarcinoma cells (HCT116) were treated with exogenous long-chain ceramides (C16-ceramide) in order to mimic endogenous sphingolipids. This treatment induced a decrease of cell viability partly due to apoptosis as shown by PARP cleavage and a decrease of pro-caspase 3. Two-dimensional differential in-gel electrophoresis (2D-DIGE) revealed the differential expression of 51 proteins in response to C16-ceramide. These proteins are notably involved in cell proliferation, apoptosis, protein transport and transcriptional regulation. Among them, the cell death-promoting factor Btf was found to be implicated in the apoptotic signal triggered by ceramide. In adenocarcinoma cells, Btf regulates apoptosis related proteins such as Mdm2, p53, BAX and pBcl-2 and thus plays an important role in the ceramide mediated cell death. These findings bring new insight into the proapoptotic ceramide-dependent signaling pathway.
Rénert
Anne-Françoise
AF
GIGA Signal Transduction, Unit of Medical Chemistry, University of Liège, Sart-Tilman, Belgium.
Leprince
Pierre
P
Dieu
Marc
M
Renaut
Jenny
J
Raes
Martine
M
Bours
Vincent
V
Chapelle
Jean-Paul
JP
Piette
Jacques
J
Merville
Marie-Paule
MP
Fillet
Marianne
M
D000230:Adenocarcinoma / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival; D002518:Ceramides / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D045325:HCT116 Cells; D006801:Humans; D020543:Proteome / Q000187:drug effects / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D015203:Reproducibility of Results; D015398:Signal Transduction; D053719:Tandem Mass Spectrometry; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
C494826:BAX protein, human; C119386:BCLAF1 protein, human; D002518:Ceramides; D020543:Proteome; D012097:Repressor Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D051028:bcl-2-Associated X Protein; C097760:N-palmitoylsphingosine; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2