Pharmacological Characterization of [F]-FNM and Evaluation of NMDA Receptors Activation in a Rat Brain Injury Model.

Purpose: NMDA receptors (NMDARs) dysfunction plays a central role in the physiopathology of psychiatric and neurodegenerative disorders whose mechanisms are still poorly understood. The development of a PET (positron emission tomography) tracer able to selectively bind to the NMDARs intra-channel PCP site may make it possible to visualize NMDARs in an open and active state. We describe the in vitro pharmacological characterization of [F]-fluoroethylnormemantine ([F]-FNM) and evaluate its ability to localize activated NMDA receptors in a rat preclinical model of excitotoxicity.

-Heterocyclic Carbene-Iridium Complexes as Photosensitizers for In Vitro Photodynamic Therapy to Trigger Non-Apoptotic Cell Death in Cancer Cells.

A series of seven novel iridium complexes were synthetized and characterized as potential photosensitizers for photodynamic therapy (PDT) applications. Among them, four complexes were evaluated in vitro for their anti-proliferative activity with and without irradiation on a panel of five cancer cell lines, namely PC-3 (prostate cancer), T24 (bladder cancer), MCF7 (breast cancer), A549 (lung cancer) and HeLa (cervix cancer), and two non-cancerous cell models (NIH-3T3 fibroblasts and MC3T3 osteoblasts). After irradiation at 458 nm, all tested complexes showed a strong selectivity against cancer cells, with a selectivity index (SI) ranging from 8 to 34 compared with non-cancerous cells.

Sphingosine 1-Phosphate Receptor 5 (S1P5) Deficiency Promotes Proliferation and Immortalization of Mouse Embryonic Fibroblasts.

Sphingosine 1-phosphate (S1P), a bioactive lipid, interacts with five widely expressed G protein-coupled receptors (S1P1-5), regulating a variety of downstream signaling pathways with overlapping but also opposing functions. To date, data regarding the role of S1P5 in cell proliferation are ambiguous, and its role in controlling the growth of untransformed cells remains to be fully elucidated. In this study, we examined the effects of S1P5 deficiency on mouse embryonic fibroblasts (MEFs).

Sphingosine Kinase-1 Is Overexpressed and Correlates with Hypoxia in Osteosarcoma: Relationship with Clinicopathological Parameters.

The Sphingosine kinase-1/Sphingosine 1-Phosphate (SphK1/S1P) signaling pathway is overexpressed in various cancers, and is instrumental for the adaptation to hypoxia in a number of solid tumor models, but no data are available in osteosarcoma. Here we report that SphK1 and the S1P receptor are involved in HIF-1α accumulation in hypoxic osteosarcoma cells. FTY720 (Fingolimod), which targets SphK1 and S1P prevented HIF-1α accumulation, and also inhibited cell proliferation in both normoxia and hypoxia unlike conventional chemotherapy.

Inhibition of sphingosine 1-phosphate protects mice against chondrocyte catabolism and osteoarthritis.

Objective: Cartilage loss observed in osteoarthritis (OA) is prevented when osteoclasts in the subchondral bone are inhibited in mice. Here, we investigated the role of the osteoclast secretome and of the lipid mediator sphingosine 1-phosphate (S1P) in chondrocyte metabolism and OA.

Materials And Methods: We used SphK1 and wild type mice to assess the effect of murine osteoclast secretome in chondrocyte metabolism.

Increased phospholipase D activity contributes to tumorigenesis in prostate cancer cell models.

Prostate cancer (PCa) is the most frequent cancer among men and the first cause of death over 65. Approximately 90% of patients with advanced disease will develop bone metastasis, which dramatically reduces long-term survival. Therefore, effective therapies need to be developed, especially when disease is still well-localized.

An Artemisinin-Derivative-(NHC)Gold(I) Hybrid with Enhanced Cytotoxicity through Inhibition of NRF2 Transcriptional Activity.

A family of hybrid complexes combining two biologically active motifs, an artemisinin derivative and a cationic bis(NHC)-gold(I) unit, has been synthesized. One of these complexes, 2 a, has been analyzed by single-crystal X-ray diffraction. 2 a shows strong anticancer activities on a large panel of human cancer cell models (prostate, breast, lung, liver, bladder, bone, acute and chronic myeloid leukemias) with GI values in the nm range, together with a high selectivity.

[Multiple sclerosis and immuno-modulators of sphingosine 1-phosphate receptors].

Multiple sclerosis (MS) is a disease of the central nervous system with a very debilitating inflammatory component that usually affects young people (years 20-40). This disease is characterized by the progressive destruction of the myelin sheath of the axons by the cells of the immune system, which results in neuronal degeneration. The T and B lymphocytes are the main players in this disease, which can be remittent with relapses or progressive.

The role of sphingosine 1-phosphate metabolism in bone and joint pathologies and ectopic calcification.

Sphingolipids display important functions in various pathologies such as cancer, obesity, diabetes, cardiovascular or neurodegenerative diseases. Sphingosine, sphingosine 1-phosphate (S1P), and ceramide are the central molecules of sphingolipid metabolism. Sphingosine kinases 1 and 2 (SK1 and SK2) catalyze the conversion of the sphingolipid metabolite sphingosine into S1P.

Sphingosine kinase-1 predicts overall survival outcomes in non-small cell lung cancer patients treated with carboplatin and navelbine.

Sphingosine 1-phosphate (S1P) is a bioactive lipid metabolite associated with cancer cell proliferation, survival, migration and regulation of tumor angiogenesis in various cellular and animal models. Sphingosine kinase-1 (SphK1) and S1P lyase are the main enzymes that respectively control the synthesis and degradation of S1P. The present study analyzed the prognostic and predictive value of SphK1 and S1P lyase expression in patients with non-small cell lung cancer (NSCLC), treated with either surgery alone or in combination with adjuvant carboplatin and navelbine.

Development and characterization of sphingosine 1-phosphate receptor 1 monoclonal antibody suitable for cell imaging and biochemical studies of endogenous receptors.

Although sphingosine-1-phosphate receptor 1 (S1P1) has been shown to trigger several S1P targeted functions such as immune cell trafficking, cell proliferation, migration, or angiogenesis, tools that allow the accurate detection of endogenous S1P1 localization and trafficking remain to be obtained and validated. In this study, we developed and characterized a novel monoclonal S1P1 antibody. Mice were immunized with S1P1 produced in the yeast Pichia pastoris and nine hybridoma clones producing monoclonal antibodies were created.

Pharmacomodulation on Gold-NHC complexes for anticancer applications - is lipophilicity the key point?

A series of four new mononuclear cationic gold(I) complexes containing nitrogen functionalized N-heterocyclic carbenes (NHCs) was synthesized and fully characterized by spectroscopic methods. The X-ray structures of three complexes are presented. These lipophilic gold(I) complexes originate from a pharmacomodulation of previously described gold(I)-NHC complexes, by replacing an aliphatic spacer with an aromatic one.

Neuronal sphingosine kinase 2 subcellular localization is altered in Alzheimer's disease brain.

Background: Alzheimer's disease (AD) is characterized by the accumulation of β-amyloid (Aβ) peptides and hyperphosphorylated tau protein accompanied by neuronal loss. Aβ accumulation has been associated with an impaired sphingosine 1-phosphate (S1P) metabolism. S1P is generated by sphingosine kinases (SphKs), of which there are two isoenzymes SphK1 and SphK2, and degraded by the sphingosine 1-phosphate lyase (SPL).

Cationic and Neutral N-Heterocyclic Carbene Gold(I) Complexes: Cytotoxicity, NCI-60 Screening, Cellular Uptake, Inhibition of Mammalian Thioredoxin Reductase, and Reactive Oxygen Species Formation.

A structurally diverse library of 14 gold(I) cationic bis(NHC) and neutral mono(NHC) complexes (NHC: N-heterocyclic carbene) was synthesized and characterized in this work. Four of them were new cationic gold(I) complexes containing functionalized NHCs, and their X-ray crystal structures are presented herein. All of the complexes were investigated for their anticancer activities in four cancer cell lines, including a cisplatin-resistant variant, and a noncancerous cell line.

Sphingosine 1-phosphate signaling through its receptor S1P promotes chromosome segregation and mitotic progression.

Sphingosine kinase 1 (SphK1) promotes cell proliferation and survival, and its abundance is often increased in tumors. SphK1 produces the signaling lipid sphingosine 1-phosphate (S1P), which activates signaling cascades downstream five G protein-coupled receptors (S1P) to modulate vascular and immune system function and promote proliferation. We identified a new function of the SphK1-S1P pathway specifically in the control of mitosis.

The therapeutic potential of HIF-2 antagonism in renal cell carcinoma.

Hypoxia, the insufficient delivery of oxygen for the demand of a tissue, contributes to the development of an aggressive phenotype, resistance to radiation therapy and chemotherapy, and is predictive of a poor outcome in numerous tumor types. Adaptation to hypoxia is mediated by hypoxia-inducible factors (HIFs), including HIF-1α and HIF-2α, which regulate genes promoting angiogenesis, increased tumor growth or metastasis. In kidney cancer, HIF-2α is believed to be the most important driver for development and progression of clear cell renal cell carcinoma (ccRCC), highlighting the therapeutic potential of HIF-2 antagonists in this disease.

FTY720 (Fingolimod) Inhibits HIF1 and HIF2 Signaling, Promotes Vascular Remodeling, and Chemosensitizes in Renal Cell Carcinoma Animal Model.

Clear cell renal cell carcinoma (ccRCC) is characterized by intratumoral hypoxia and chemoresistance. The hypoxia-inducible factors HIF1α and HIF2α play a crucial role in ccRCC initiation and progression. We previously identified the sphingosine kinase 1/sphingosine 1-phosphate (SphK1/S1P) pathway as a new modulator of HIF1α and HIF2α under hypoxia in various cancer cell models.

Essential role for SphK1/S1P signaling to regulate hypoxia-inducible factor 2α expression and activity in cancer.

The sphingosine kinase-1/sphingosine 1-phosphate (SphK1/S1P) signaling pathway has been reported to modulate the expression of the canonical transcription factor hypoxia-inducible HIF-1α in multiple cell lineages. HIF-2α is also frequently overexpressed in solid tumors but its role has been mostly studied in clear cell renal cell carcinoma (ccRCC), the most common form of kidney cancer, where HIF-2α has been established as a driver of a more aggressive disease. In this study, the role of SphK1/S1P signaling with regard to HIF-2α was investigated in various cancer cell models including ccRCC cells.

[Mechanisms of castration resistance: Intratumoral hypoxia stimulates the androgen receptor expression].

Purpose: Tumor hypoxia and its biological consequence lead to microenvironment adaptation of tumor initiation, promotion and progression. The aim of the study was to observe the influence of hypoxia on the expression of the androgen receptor (AR), using an original model of multicellular spheroids obtained from castration-resistant prostate tumor cells.

Material: Two human castration-resistant prostate cancer cell lines have been used to generate multicellular tumor spheroids (MTS).

Neutralizing S1P inhibits intratumoral hypoxia, induces vascular remodelling and sensitizes to chemotherapy in prostate cancer.

Hypoxia promotes neovascularization, increased tumor growth, and therapeutic resistance. The transcription factor, hypoxia-inducible factor 1α (HIF-1α), has been reported as the master driver of adaptation to hypoxia. We previously identified the sphingosine kinase 1/sphingosine 1-phosphate (SphK1/S1P) pathway as a new modulator of HIF-1α under hypoxia.

Inhibition of the GTPase Rac1 mediates the antimigratory effects of metformin in prostate cancer cells.

Cell migration is a critical step in the progression of prostate cancer to the metastatic state, the lethal form of the disease. The antidiabetic drug metformin has been shown to display antitumoral properties in prostate cancer cell and animal models; however, its role in the formation of metastases remains poorly documented. Here, we show that metformin reduces the formation of metastases to fewer solid organs in an orthotopic metastatic prostate cancer cell model established in nude mice.