3-Ketosphinganine provokes the accumulation of dihydroshingolipids and induces autophagy in cancer cells

Yadira F. Ordóñez, Jèssica González, Carmen Bedia, Josefina Casas, José Luis Abad, Antonio Delgado, Gemma Fabrias

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11 Scopus citations

Abstract

Although several reports describe the metabolic fate of sphingoid bases and their analogs, as well as their action and that of their phosphates as regulators of sphingolipid metabolizing-enzymes, similar studies for 3-ketosphinganine (KSa), the product of the first committed step in de novo sphingolipid biosynthesis, have not been reported. In this article we show that 3-ketosphinganine (KSa) and its dideuterated analog at C4 (d2KSa) are metabolized to produce high levels of dihydrosphingolipids in HGC27, T98G and U87MG cancer cells. In contrast, either direct C1 O-phosphorylation or N-acylation of d2KSa to produce dideuterated ketodihydrosphingolipids does not occur. We also show that cells respond to d2KSa treatment with induction of autophagy. Time-course experiments agree with sphinganine, sphinganine 1-phosphate and dihydroceramides being the mediators of autophagy stimulated by d2KSa. Enzyme inhibition studies support that inhibition of Des1 by 3-ketobases is caused by their dihydroceramide metabolites. However, this effect contributes to increasing dihydrosphingolipid levels only at short incubation times, since cells respond to long time exposure to 3-ketobases with Des1 overexpression. The translation of these overall effects into cell fate is discussed.

Original languageEnglish
Pages (from-to)1166-1173
Number of pages8
JournalMolecular BioSystems
Volume12
Issue number4
DOIs
StatePublished - 2016
Externally publishedYes

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© The Royal Society of Chemistry 2016.

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