Secretory acid sphingomyelinase activity is elevated in persons with colorectal neoplasia

BackgroundMetabolomic changes related to colorectal cancer (CRC) may serve as diagnostic markers to identify patients may develop or have developed CRC. MethodsUntargeted lipidomics were performed on serum from CRC cases and clean-colon controls from the Chicago Colorectal Cancer Consortium (CCCC) and the University of Arizona Cancer Center (UACC). ResultsUntargeted lipidomics in the CCCC CRC series revealed significant alterations in sphingolipids. Targeted lipidomics revealed a signature of five sphingomyelins (SMs) were significantly decreased in CRC patients in CCCC and UACC CRC series. Circulating SMs are degraded primarily by S-SMase and serum S-SMase activity was significantly higher in UACC cases as compared to controls. Serum S-SMase activity was also measured in two series of adenoma patients to determine if S-SMase may serve as a biomarker for development of colorectal neoplasia. While S-SMase activity was significantly higher in adenoma patients compared to controls in the mostly white UACC series, S-SMase activity in samples from the Chicago Black series (CCCC) were indistinguishable from each other and significantly higher than UACC controls. ConclusionsTogether, these studies suggest the potential for S-SMase activity to serve as a biomarker for colorectal neoplasia, with potential implications in some but perhaps not all populations.