Tissue sphinganine as a biomarker of fumonisin-induced apoptosis

NCTR measured sphinganine concentrations in the livers of mice and in the livers and kidneys of rats in conjunction with a tumour bioassay. In our model of the tumour incidence, target-tissue levels of sphinganine serve as a biomarker for a dose response of fumonisin B-1 on cell death. Initially we questioned the utility of sphinganine levels in this role because they were highly variable when compared across time points. In spite of this concern, a conceptual framework and data are presented that support the use of sphinganine as a biomarker for a dose response of fumonisin B-1 on cell death. This framework is reasonably consistent with observed sphinganine concentrations in the examined tissues, the literature on fumonisin's effects on sphingolipid synthesis, and our hypothesized mechanism through which fumonisin B-1 increases age-specific tumour incidence.