Search results for "Sphingosine kinase"
showing 7 items of 7 documents
Comparative analysis of the effects of a sphingosine kinase inhibitor to temozolomide and radiation treatment on glioblastoma cell lines.
2017
ABSTRACT Glioblastoma multiforme (GBM) exhibits high resistance to the standard treatment of temozolomide (TMZ) combined with radiotherapy, due to its remarkable cell heterogeneity. Accordingly, there is a need to target alternative molecules enhancing specific GBM autocrine or paracrine mechanisms and amplifying the effect of standard treatment. Sphingosine 1-phosphate (S1P) is such a lipid target molecule with an important role in cell invasion and proliferation. Sphingosine kinase inhibitors (SKI) prevent S1P formation and induce increased production of reactive oxygen species (ROS), which may potentiate radiation cytotoxicity. We analyzed the effect of SKI singular versus combined treat…
The sphingosine kinase 1 activator, K6PC-5, attenuates Ebola virus infection
2021
Summary Ebola virus (EBOV) is responsible for outbreaks with case fatality rates of up to 90% and for an epidemic in West Africa with more than ten thousand deaths. EBOV glycoprotein (EBOV-GP) is the only viral surface protein and is responsible for viral entry into cells. Here, by employing pseudotyped EBOV-GP viral particles, we uncover a critical role for sphingolipids in inhibiting viral entry. Sphingosine kinase 1 (SphK1) catalyzes the phosphorylation of sphingosine to sphingosine 1-phosphate (S1P). The administration of the SphK1 activator, K6PC-5, or S1P, or the overexpression of SphK1 consistently exhibited striking inhibitory effects in EBOV-GP-driven entry in diverse cell lines. F…
An active form of sphingosine kinase-1 is released in the extracellular medium as component of membrane vesicles shed by two human tumor cell line.
2010
Expression of sphingosine kinase-1 (SphK-1) correlates with a poor survival rate of tumor patients. This effect is probably due to the ability of SphK-1 to be released into the extracellular medium where it catalyzes the biosynthesis of sphingosine-1-phosphate (S1P), a signaling molecule endowed with profound proangiogenic effects. SphK-1 is a leaderless protein which is secreted by an unconventional mechanism. In this paper, we will show that in human hepatocarcinoma Sk-Hep1 cells, extracellular signaling is followed by targeting the enzyme to the cell surface and parallels targeting of FGF-2 to the budding vesicles. We will also show that SphK-1 is present in a catalitycally active form i…
A sphingosine kinase inhibitor combined with temozolomide induces glioblastoma cell death through accumulation of dihydrosphingosine and dihydroceram…
2014
AbstractGlioblastomas (GBMs) are very aggressive tumors with low chemosensitivity. The DNA-alkylating agent temozolomide (TMZ) is currently the most efficient chemotoxic drug for GBM therapy; however, many patients develop resistance to TMZ. Combining TMZ with another agent could present an improved treatment option if it could overcome TMZ resistance and avoid side effects. Sphingosine kinase inhibitors (SKIs) have emerged as anticancer agents. Sphingosine kinases are often overexpressed in tumors where their activity of phosphorylating sphingosine (Sph) contributes to tumor growth and migration. They control the levels of the pro-apoptotic ceramide (Cer) and Sph and of the pro-survival sp…
Cardioprotection by gene therapy
2015
Ischemic heart disease remains the leading cause of death worldwide. Ischemic pre-, post-, and remote conditionings trigger endogenous cardioprotection that renders the heart resistant to ischemic-reperfusion injury (IRI). Mimicking endogenous cardioprotection by modulating genes involved in cardioprotective signal transduction provides an opportunity to reproduce endogenous cardioprotection with better possibilities of translation into the clinical setting. Genes and signaling pathways by which conditioning maneuvers exert their effects on the heart are partially understood. This is due to the targeted approach that allowed identifying one or a few genes associated with IRI and cardioprote…
The Sphingosine Kinase-1 Activator, K6PC-5, Attenuates the Ebola Virus Infection and the Virus Induced Cell Death
2020
Ebola virus (EBOV) is responsible for outbreaks with case-fatality rates of up to 90% and for an epidemic in West Africa with more than ten thousand deaths. EBOV glycoprotein (EBOV-GP) is the only viral surface protein and is responsible for viral entry into cells. It has been suggested to play a role in the cytopathic effects induced by the virus. Here we uncover a critical role for sphingolipids in inhibiting viral entry and virus-mediated cytotoxicity. Sphingosine kinase 1 (SphK1) catalyzes the phosphorylation of sphingosine to sphingosine-1-phosphate (S1P). The administration of the SphK1 activator, K6PC-5, or S1P, or the overexpression of SphK1 consistently exhibited striking inhibito…
Synthesis and biological evaluation of sphingosine kinase 2 inhibitors with anti-inflammatory activity.
2019
The synthesis of inhibitors of SphK2 with novel structural scaffolds is reported. These compounds were designed from a molecular modeling study, in which the molecular interactions stabilizing the different complexes were taken into account. Particularly interesting is that 7‐bromo‐2‐(2‐phenylethyl)‐2,3,4,5‐tetrahydro‐1,4‐epoxynaphtho[1,2‐b]azepine, which is a selective inhibitor of SphK2, does not exert any cytotoxic effects and has a potent anti‐inflammatory effect. It was found to inhibit mononuclear cell adhesion to the dysfunctional endothelium with minimal impact on neutrophil–endothelial cell interactions. The information obtained from our theoretical and experimental study can be us…