Bioactive Lipids S1P and C1P Are Prometastatic Factors in Human Rhabdomyosarcoma, and Their Tissue Levels Increase in Response to Radio/Chemotherapy

Abstract

We observed that sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P) strongly enhance in vitro motility and adhesion of human rhabdomyosarcoma (RMS) cells. This effect was observed at physiological concentrations of both bioactive lipids, which are present in biological fluids, and is much stronger than the effects observed in response to known RMS pro-metastatic factors such as stromal derived factors-1 (SDF-1) or hepatocyte growth factor/scatter factor (HGF/SF). We also present novel evidence that the levels of S1P and C1P increase in several organs after γ-irradiation or chemotherapy, which indicates induction of an unwanted pro-metastatic environment related to treatment. Most importantly, we found that the metastasis of RMS cells in response to S1P can be effectively inhibited in vivo with the S1P-specific binder NOX-S93 that is based on a high affinity Spiegelmer. We propose that bioactive lipids play a previously underappreciated role in dissemination of RMS and the unwanted side effects of radio/chemotherapy by creating a pro-metastatic microenvironment. Therefore, an anti-metastatic treatment with specific S1P-binding scavenger such as NOX-S93 could become a part of standard radio/chemotherapy.

ORMDL/serine palmitoyltransferase stoichiometry determines effects of ORMDL3 expression on sphingolipid biosynthesis

“…Prior to extraction, a mixture of C17 sphingolipids was added to each sample (125 pmol/sample, Avanti sphingolipid mix #1) as internal standards. Sphingolipids were quantitated by HPLC electrospray ionization tandem mass spectrometry using selected ion monitoring on an ABSciex 4000 Q-Trap instrument as described previously (13)(14)(15). Total phospholipids for each sample were measured using a modifi ed Ames and Dubin assay ( 16 ), as previously described ( 12 ).…”

Regulation of de novo sphingolipid biosynthesis by the ORMDL proteins and sphingosine kinase-1

“…A mixture of C17 sphingolipids (Avanti sphingolipid mix #1, Avanti, Alabaster, AL, 125 pMol/sample) was added to each prior to extraction. Sphingolipids were quantitated by HPLC electrospray ionization tandem mass spectrometry using selected ion monitoring on an ABSciex 4000 Q-Trap instrument as described previously (Deevska et al, 2012;Salous et al, 2013;Schneider et al, 2013). Total phospholipids for each sample were measured using a modified Ames and Dubin assay (Ames and Dubin, 1960) as previously described (Siow et al, 2010).…”

Caged ceramide 1-phosphate (C1P) analogs: Novel tools for studying C1P biology

“…The stimulation of cell motility involved interaction of C1P with a Gi protein-coupled plasma membrane receptor, which upon ligation with C1P caused the release of macrophage chemoattractant protein 1 (MCP-1) and subsequent activation of the PI3K/PKB (Akt) and MEK/ERK1-2 pathways Granado et al, 2009b). The stimulation of cell migration by C1P involving interaction with a Gi protein-coupled (PTX-sensitive) receptor has been recently confirmed by other groups (Karapetyan et al, 2013;Kim et al, 2013Kim et al, , 2011Ratajczak et al, 2010Ratajczak et al, , 2014Schneider et al, 2013).…”