In the US, the incidence and mortality of many
cancers are disproportionately higher in African Americans (AA). Yet, AA remain poorly represented in molecular studies investigating the roles that
biological factors might play in the development, progression, and outcomes of many
cancers. Given that
sphingolipids, key components of mammalian cellular membranes, have well-established roles in the etiology of
cancer progression,
malignancy, and responses to
therapy, we conducted a robust mass spectrometry analysis of
sphingolipids in normal adjacent uninvolved tissues and
tumors of self-identified AA and non-Hispanic White (NHW) males with
cancers of the lung, colon, liver, and head and neck and of self-identified AA and NHW females with
endometrial cancer. In these
cancers, AA have worse outcomes than NHW. The goal of our study was to identify biological candidates to be evaluated in future preclinical studies targeting race-specific alterations in the
cancers of AA. We have identified that various
sphingolipids are altered in race-specific patterns, but more importantly, the ratios of 24- to 16-carbon fatty acyl chain-length
ceramides and
glucosylceramides are higher in the
tumors of AA. As there is evidence that
ceramides with 24-carbon
fatty acid chain length promote cellular survival and proliferation, whereas 16-carbon chain length promote apoptosis, these results provide important support for future studies tailored to evaluate the potential roles these differences may play in the outcomes of AA with
cancer.