Grace Feucht, “Identifying Unique Fragmentation of Ceramides via Gas Chromatography-Mass Spectrometry”
Mentor: Shama Mirza, Chemistry & Biochemistry
Poster #57

Ceramides are a group of sphingolipids with a key role in many necessary cellular processes such as growth, differentiation, cell cycle arrest, senescence, and apoptosis. To avoid cell death, ceramides can be converted to sphingosine-1-phosphate (S1P). S1P is a signaling lipid and an important regulator of angiogenesis, cardiogenesis, neurogenesis, cell migration, and survival. SP1 has been found to be expressed in high levels in glioblastoma (GBM), a malignant fast growing brain tumor. Thus, S1P is known to be a tumor promotor while ceramides are tumor suppressors. Therefore, it is important to measure the ceramides in tumors compared to healthy tissues to understand the pathophysiology of disease. This leads to efficient drug discovery targeting ceramide signaling pathway in lethal diseases like glioblastoma and other cancers. Ceramides being nonvolatile, liquid chromatography-mass spectrometry (LC-MS) is a method of choice for analyzing these compounds. However, not all compounds have the same ionization efficiency and hence have differential identification at any given experimental condition. To expand the spectrum of ceramide identification, we used gas chromatography-mass spectrometry (GC-MS) after derivatizing the compounds to enhance the identification efficiency. Mixed ceramide standards were derivatized using trimethylchlorosilane (TMCS) and N,O-bis-(trimethylsilyl)-acetamide (BSA). The ceramide mixture was then heated in a water bath for several hours to complete the reaction. The samples were then analyzed on a Shimadzu QP2010 GC-MS for identification and Shimadzu LC-MS 2020 for verification of the ceramide derivatives. GC-MS provided a unique fragmentation of the standard ceramides compared to LC-MS analysis. Identification of complex mixture of ceramides from in vitro samples is underway.