RGDfV increases ceramides and decreases sphingomyelins, and these changes are abrogated following ASM. knockdown.

Lysates of cells treated with siRNA and RGDfV as in Figs. 2C–D as were analyzed by mass spectrometry as detailed in Methods. Sphingolipid nomenclature: Ceramides are 1,3-hydroxy-2-amino alkanes (sphinganine) or alkenes (sphingosine) with fatty acid alkyl chains of C14 to C24 linked to the amino group of the sphingosine or sphinganine. A double bond in fatty acid alkyl chains is indicated as number “1” in the name. For example, C14-CER is sphingosine + C14 fatty acid without a double bond, and C18:1-CER is sphingosine + C18 fatty acid with a double bond. Sphingomyelins (SM) have sphingosine with the 1-hydroxyl group modified to phosphocholine as a core structural moiety, and the numbers for SM are the number of carbons of fatty acid chain. The levels of C20:1-CER, C22:1-CER and C20:1-SM were below the level of detection and were thus were not included in the table. Shown are means of three independent experiments ± SEM. NS: not statistically significant.