This study identifies a target for the action of resveratrol and its higher order oligomers and opens the door to evaluation of SphK1 as a target for chemo-prevention of cancer

This study identifies a target for the action of resveratrol and its higher order oligomers and opens the door to evaluation of SphK1 as a target for chemo-prevention of cancer. LINKED ARTICLE This short article is a commentary on Lim et al., pp. it was realized that other mechanisms must be responsible for the anti-cancer effects (Baur et al., 2006). In this issue of the British Journal of Pharmacology, Lim et al. (2012) describe a novel role for resveratrol and its higher order oligomers in inhibition of sphingosine kinase 1 (SphK1). SphK1 is an oncogenic lipid kinase that generates pro-mitogenic sphingosine-1-phosphate (S1P) from your substrate d-erythro-sphingosine (Sph). Sphingosine itself is usually generated by the de-acylation of ceramide a well-documented pro-apoptotic sphingolipid (Ponnusamy et al., 2010). S1P is usually a potent first and second messenger molecule that has both intracellular and extracellular actions primarily through activation of pro-mitogenic and pro-survival signalling cascades (MAP kinase and PI3 kinase cascades respectively; Pyne and Pyne, 2011). Similarly, ceramide is usually a potent inducer of apoptotic signalling and is generated in response to many chemotherapeutic agents. Thus, Tenapanor SphK1, like its isoenzyme SphK2, is usually precariously perched at the balance point between pro-growth and pro-death signalling in the cell. Klf2 The balance of ceramide and S1P has been termed the sphingolipid rheostat and Tenapanor alteration of this balance is usually a key determinant of cellular fate. Perturbation of the sphingolipid Tenapanor rheostat, favouring the production of S1P at the expense of ceramide, is usually a core feature of many hyperproliferative diseases including malignancy and inflammatory diseases. Recent studies have added additional layers of complexity to the sphingolipid rheostat concept. The demonstration that ceramide species of different acyl chain lengths have unique and opposing functions in regulation of apoptotic signalling has initiated a dogmatic shift in the sphingolipid field (Hartmann et al., 2012). Similarly, a better understanding of the metabolic breakdown of S1P has exhibited that S1P levels are not static (Loh et al., 2011). Thus, we can no longer consider only the steady-state levels of ceramide and S1P when evaluating sphingolipid metabolic enzyme inhibitors. Together, these studies highlight the complexity and interconnectedness of the sphingolipid metabolites and reinforce the idea that this sphingolipid metabolic pathway is usually a rich source of new therapeutic targets. Because of its unique role in the cell, SphK1 has been recognized, for years, as a potential target for the development of anti-cancer and anti-inflammatory strategies and this has been borne out in numerous studies (Pyne et al., 2011). Numerous inhibitors of SphK have been identified including substrate analogues (i.e. dimethylsphingosine) and small molecule inhibitors. Recent advances have seen the identification of isotype specific inhibitors and inhibition of either SphK1 or SphK2 seems to have the potential for future therapeutic development. Studies such as those of Lim et al. (2012) Tenapanor have several important outcomes. First and foremost, they identify a novel target for the actions of resveratrol and its higher order oligomers. The observation that resveratrol dimers are more potent than resveratrol itself is intriguing. Given that these authors have also recently identified SphK as a minimal dimer, it is tempting to speculate that the larger resveratrol oligomers are binding to multiple SphK molecules simultaneously. Identification of the residues of SphK required for resveratrol binding could therefore serve as a way to gain important knowledge about the oligomeric structure of SphK. Further studies of the oligomerization of SphK1 and whether it can.