A new family of choline kinase inhibitors with antiproliferative and antitumor activity derived from natural products.

BACKGROUND: Choline kinase alpha (ChoKα) is a critical enzyme in the synthesis of phosphatidylcholine, a major structural component of eukaryotic cell membranes. ChoKα is overexpressed in a large variety of tumor cells and has been proposed as a target for personalized medicine, both in cancer therapy and rheumatoid arthritis. MATERIALS AND METHODS: Triterpene quinone methides (TPQ) bioactive compounds isolated from plants of the Celastraceae family and a set of their semisynthetic derivatives were tested against the recombinant human ChoKα. Those found active as potent enzymatic inhibitors were tested in vitro for antiproliferative activity against HT29 colorectal adenocarcinoma cells, and one of the active compounds was tested for in vivo antitumoral activity in mice xenographs of HT29 cells. RESULTS: Among 59 natural and semisynthetic TPQs tested in an ex vivo system, 14 were highly active as inhibitors of the enzyme ChoKα with IC50 <10 µM. Nine of these were potent antiproliferative agents (IC50 <10 µM) against tumor cells. At least one compound was identified as a new antitumoral drug based on its in vivo activity against xenographs of human HT-29 colon adenocarcinoma cells. CONCLUSIONS: The identification of a new family of natural and semisynthetic compounds with potent inhibitory activity against ChoKα and both in vitro antiproliferative and in vivo antitumoral activity supports further research on these inhibitors as potential anticancer agents. Their likely role as antiproliferative drugs deserves further studies in models of rheumatoid arthritis.

Choline kinase inhibition in rheumatoid arthritis.

OBJECTIVES: Little is known about targeting the metabolome in non-cancer conditions. Choline kinase (ChoKα), an essential enzyme for phosphatidylcholine biosynthesis, is required for cell proliferation and has been implicated in cancer invasiveness. Aggressive behaviour of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA) led us to evaluate whether this metabolic pathway could play a role in RA FLS function and joint damage. METHODS: Choline metabolic profile of FLS cells was determined by (1)H magnetic resonance spectroscopy ((1)HMRS) under conditions of ChoKα inhibition. FLS function was evaluated using the ChoKα inhibitor MN58b (IC50=4.2 µM). For arthritis experiments, mice were injected with K/BxN sera. MN58b (3 mg/kg) was injected daily intraperitoneal beginning on day 0 or day 4 after serum administration. RESULTS: The enzyme is expressed in synovial tissue and in cultured RA FLS. Tumour necrosis factor (TNF) and platelet-derived growth factor (PDGF) stimulation increased ChoKα expression and levels of phosphocholine in FLS measured by Western Blot (WB) and metabolomic studies of choline-containing compounds in cultured RA FLS extracts respectively, suggesting activation of this pathway in RA synovial environment. A ChoKα inhibitor also suppressed the behaviour of cultured FLS, including cell migration and resistance to apoptosis, which might contribute to cartilage destruction in RA. In a passive K/BxN arthritis model, pharmacologic ChoKα inhibition significantly decreased arthritis in pretreatment protocols as well as in established disease. CONCLUSIONS: These data suggest that ChoKα inhibition could be an effective strategy in inflammatory arthritis. It also suggests that targeting the metabolome can be a new treatment strategy in non-cancer conditions.

Rho GTPase Rac1: molecular switch within the galectin network and for N-glycan α2,6-sialylation/O-glycan core 1 sialylation in colon cancer in vitro.

The Rho GTPase Rac1 is a multifunctional protein working through different effector pathways. The emerging physiological significance of glycanlectin recognition gives reason to testing the possibility for an influence of modulation of Rac1 expression on these molecular aspects. Using human colon adenocarcinoma (SW620) cells genetically engineered for its up- and down-regulation (Rac1+ and Rac1- cells) along with wild-type and mock-transfected control cells, the questions are addressed whether the presence of adhesion/growth-regulatory galectins and distinct aspects of cell surface glycosylation are affected. Proceeding from RT-PCR data to Western blotting after two-dimensional gel electrophoresis and flow cytofluorimetry with non-crossreactive antibodies against six members of this lectin family (i.e. galectins-1, -3, -4, -7, -8 and -9), a reduced extent of the presence of galectins-1, -7 and -9 was revealed in the case of Rac1 cells. Application of these six galectins as probes to determination of cell reactivity for human lectins yielded relative increases in surface labelling of Rac1- cells with galectins-1, -3 and -7. Examining distinct aspects of cell surface glycosylation with a panel of 14 plant/fungal lectins disclosed a decrease in α2,6-sialylation of N-glycans and an increase in PNA-reactive sites (i.e. non-sialylated core 1 O-glycans), two alterations known to favour reactivity for galectins-1 and -3. Thus, manipulation of Rac1 expression selectively affects the expression pattern within the galectin network at the level of proteins and distinct aspects of cell surface glycosylation.

Variants in phospholipid metabolism and upstream regulators and non-small cell lung cancer susceptibility.

AIM: The relevance of the cytidine diphosphate-choline and Rho GTPases pathways in the pathogenesis of cancer has been previously demonstrated. We investigate by a case-control association study if genetics variants in these pathways are associated with risk of developing lung cancer. METHODS: Thirty-seven tag SNPs were evaluated as risk factor of NSCLC in 897 cases and 904 controls. RESULTS: Six SNPs were nominally associated with lung cancer risk, which were not significant after the Bonferroni correction for multiple comparisons. No association was observed with the remaining 31 analyzed SNPs, neither it was found significant in haplotype frequencies. CONCLUSIONS: Although the implication of the two pathways investigated in our study in carcinogenesis is well established, our null results suggest that common genetic variants in CDP-choline and Rho GTPases-related genes are not risk factors for lung cancer.

Tactic responses to pollutants and their potential to increase biodegradation efficiency.

A significant number of bacterial strains are able to use toxic aromatic hydrocarbons as carbon and energy sources. In a number of cases, the evolution of the corresponding degradation pathway was accompanied by the evolution of tactic behaviours either towards or away from these toxic carbon sources. Reports are reviewed which show that a chemoattraction to heterogeneously distributed aromatic pollutants increases the bioavailability of these compounds and their biodegradation efficiency. An extreme form of chemoattraction towards aromatic pollutants, termed 'hyperchemotaxis', was described for Pseudomonas putida DOT-T1E, which is based on the action of the plasmid-encoded McpT chemoreceptor. Cells with this phenotype were found of being able to approach and of establishing contact with undiluted crude oil samples. Although close McpT homologues are found on other degradation plasmids, the sequence of their ligand-binding domains does not share significant similarity with that of NahY, the other characterized chemoreceptor for aromatic hydrocarbons. This may suggest the existence of at least two families of chemoreceptors for aromatic pollutants. The use of receptor chimers comprising the ligand-binding region of McpT for biosensing purposes is discussed.

Acid ceramidase as a chemotherapeutic target to overcome resistance to the antitumoral effect of choline kinase α inhibition.

We have analyzed the response of primary cultures derived from tumor specimens of non small cell lung cancer (NSCLC) patients to choline kinase α (ChoKα) inhibitors. ChoKα inhibitors have been demonstrated to increase ceramides levels specifically in tumor cells, and this increase has been suggested as the mechanism that explain its proapoptotic effect in cancer cells. Here, we have investigated the molecular mechanism associated to the intrinsic resistance, and found that other enzyme involved in lipid metabolism, acid ceramidase (ASAH1), is specifically upregulated in resistant tumors. NSCLC cells with acquired resistance to ChoKα inhibitors also display increased levels of ASAH1. Accordingly, ASAH1 inhibition synergistically sensitizes lung cancer cells to the antiproliferative effect of ChoKα inhibitors. Thus, the determination of the levels of ASAH1 predicts sensitivity to targeted therapy based on ChoKα specific inhibition and represents a model for combinatorial treatments of ChoKα inhibitors and ASAH1 inhibitors. Considering that ChoKα inhibitors have been recently approved to enter Phase I clinical trials by the Food and Drug Administration (FDA), these findings are anticipating critical information to improve the clinical outcome of this family of novel anticancer drugs under development.

Crystallization and crystallographic analysis of the ligand-binding domain of the Pseudomonas putida chemoreceptor McpS in complex with malate and succinate.

Methyl-accepting chemotaxis proteins (MCPs) are transmembrane proteins that sense changes in environmental signals, generating a chemotactic response and regulating other cellular processes. MCPs are composed of two main domains: a ligand-binding domain (LBD) and a cytosolic signalling domain (CSD). Here, the crystallization of the LBD of the chemoreceptor McpS (McpS-LBD) is reported. McpS-LBD is responsible for sensing most of the TCA-cycle intermediates in the soil bacterium Pseudomonas putida KT2440. McpS-LBD was expressed, purified and crystallized in complex with two of its natural ligands (malate and succinate). Crystals were obtained by both the counter-diffusion and the hanging-drop vapour-diffusion techniques after pre-incubation of McpS-LBD with the ligands. The crystals were isomorphous and belonged to space group C2, with two molecules per asymmetric unit. Diffraction data were collected at the ESRF synchrotron X-ray source to resolutions of 1.8 and 1.9 Å for the malate and succinate complexes, respectively.

Approaches for the study of cancer: towards the integration of genomics, proteomics and metabolomics

Recent technological advances, combined with the development of bioinformatic tools, allow us to better address biological questions combining -omic approaches (i.e., genomics, metabolomics and proteomics). This novel comprehensive perspective addresses the identification, characterisation and quantitation of the whole repertoire of genes, proteins and metabolites occurring in living organisms. Here we provide an overview of recent significant advances and technologies used in genomics, metabolomics and proteomics. We also underline the importance and limits of mass accuracy in mass spectrometry-based -omics and briefly describe emerging types of fragmentation used in mass spectrometry. The range of instruments and techniques used to address the study of each -omic approach, which provide vast amounts of information (usually termed "high-throughput" technologies in the literature) is briefly discussed, including names, links and descriptions of the main databases, data repositories and resources used. Integration of multiple -omic results and procedures seems necessary. Therefore, an emerging challenge is the integration of the huge amount of data generated and the standardisation of the procedures and methods used. Functional data integration will lead to answers to unsolved questions, hopefully, applicable to clinical practice and management of patients (AU)

A critical role for choline kinase-alpha in the aggressiveness of bladder carcinomas.

Bladder cancer is one of the most common causes of death in industrialized countries. New tumor markers and therapeutic approaches are still needed to improve the management of bladder cancer patients. Choline kinase-alpha (ChoKalpha) is a metabolic enzyme that has a role in cell proliferation and transformation. Inhibitors of ChoKalpha show antitumoral activity and are expected to be introduced soon in clinical trials. This study aims to assess whether ChoKalpha plays a role in the aggressiveness of bladder tumors and constitutes a new approach for bladder cancer treatment. We show here that ChoKalpha is constitutively altered in human bladder tumor cells. Furthermore, in vivo murine models, including an orthotopic model to mimic as much as possible the physiological conditions, revealed that increased levels of ChoKalpha potentiate both tumor formation (P< or =0.0001) and aggressiveness of the disease on different end points (P=0.011). Accordingly, increased levels of ChoKalpha significantly reduce survival of mice with bladder cancer (P=0.05). Finally, treatment with a ChoKalpha-specific inhibitor resulted in a significant inhibition of tumor growth (P=0.02) and in a relevant increase in survival (P=0.03).

Clinical and Translational Oncology accepted in SciSearch and journal citation reports

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Analgesia epidural y resultados obstétricos / Epidural analgesia and obstetric outcomes

Se realizó un estudio retrospectivo, descriptivo y comparativo acerca de los efectos de la analgesia epidural frente a no analgesia epidural en el parto, en una muestra de 1.928 partos acontecidos en un período de 3 años y se atendió a una serie de parámetros que se pueden ver influenciados de manera positiva o negativa, como son factores relacionados con las distintas fases del parto, distocias, instrumentación, índice de cesáreas, repercusiones neonatales e impacto sobre el suelo pélvico. Tras el tratamiento estadístico, se observaron diferencias significativas en la prolongación del parto, el mayor número de instrumentación, el aumento en la tasa de cesáreas y el incremento del índice de episiotomías en multíparas en los partos conducidos bajo analgesia epidural. Por el contrario, no se dieron diferencias significativas en las distocias en occipito posterior, fiebre intraparto, partos con cesárea anterior o episiotomías en primíparas. Hubo significación estadística a favor de los partos sin analgesia epidural en el número de infecciones neonatales, así como desgarros perineales de primer grado en multíparas e integridad perineal en multíparas. A tenor de estos resultados obtenidos en nuestro hospital, nos planteamos incorporar al documento de consentimiento informado sobre analgesia epidural todos los posibles efectos adversos derivados de ésta (AU)

We performed a descriptive retrospective study comparing the effects of the application versus non application of epidural analgesia during delivery in1928 women over a 3-year period. Several parameters that could be positively or negatively influenced by epidural analgesia administration, such as factors related to the different stages of delivery, dystocia, instrumentation, rate of cesarean sections, neonatal repercussion and impact on the pelvic floor, were evaluated. Statistical analysis revealed that epidural analgesia was associated with prolongation of delivery and increases in the number of instruments involved and the rates of cesarean section and episiotomy in multiparas. These differences were statistically significant. In contrast, no significant differences were found in the occurrence of dystocia in the occipito posterior position, intrapartum fever, deliveries with prior cesarian section or episiotomy in primiparas. Statistically significant differences were found in favor of deliveries without epidural analgesia in the number of neonatal infections, as well as in first degree lacerations and perineal integrity in multiparous women In view of the results obtained in our hospital, we are considering adding all the possible adverse effects associated with epidural analgesia to our informed consent document (AU)

It is about time that Spain launches a National Cancer Act?

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Correlación de la analgesia epidural en el aumento de la tasa de cesáreas / Association between epidural analgesia and increased cesarian section rate

Presentamos un estudio cuyo objetivo es definir la incidencia de la analgesia epidural (AE) sobre el índice de cesáreas. Para ello analizamos de manera retrospectiva 1.928 partos y comparamos 2 grupos: los conducidos bajo AE, frente a los partos sin epidural. Introducimos como sesgos las siguientes variables: paridad, cesárea programada, cesárea anterior y cesárea programada más cesárea previa. Al aplicar el análisis estadístico obtenemos diferencias significativas al suprimir el sesgo de cesárea programada, tanto en primíparas (p = 0,02) como en multíparas (p = 0,049); la tasa de cesáreas se incrementa en los partos con epidural (AU)

The aim of this study was to determine the effect of epidural analgesia on the cesarian section rate. To do this, we retrospectively analyzed 1928 deliveries and compared those performed under epidural analgesia with those performed without epidural analgesia. The following variables were considered as possible sources of bias: parity, elective cesarean section, previous caesarean section, and elective cesarean section plus previous caesarean section. When applying the statistical analysis, we obtained significant differences when suppressing the bias of elective cesarean section, both in primiparas (p = 0.02) and in multiparas (p = 0.049); the rate of cesarean section was increased in deliveries performed with epidural analgesia (AU)

QSAR-derived choline kinase inhibitors: how rational can antiproliferative drug design be?

This review presents an overview of Choline Kinase (ChoK) inhibitors with antiproliferative activity. The consideration of ChoK as a novel target for the development of new anticancer drugs is justified. The synthesis of several derivatives based on structural modifications of hemicholinium-3 (HC-3) is not accompanied by potentiation of the neurological toxicity of HC-3. The increment of both ChoK inhibitory and antiproliferative activities was successfully obtained by the two following changes: a) substitution of the oxazonium moiety of HC-3 by several aromatic heterocycles, and b) using the 1,2-ethylene(bisbenzyl) moiety instead of the 4,4'-biphenyl fragment. In an attempt to understand the ChoK inhibitory activity, a quantitative structure-activity relationship was developed. The QSAR equations have described the forces involved in quantitative terms. The electron characteristic of the substituent at position 4 of the heterocycle and the lipophilic character of the whole molecule were found to significantly affect the antitumour activity in compounds 17-95. Trispyridinium compounds 91-95 are more potent than the bispyridinium ones 87-89 as ChoK inhibitors. Nevertheless, 91-95 are less active than 87-89 as antiproliferative agents because the latter show better lipophilicities to cross the cytosolic membranes. Inhibition of the growth of human tumours in nude mice has been demonstrated: Antitumour activity of compound 64 against human HT-29 produced a decrease of up to 70% in the size of the tumour in nude mice. These results indicate that ChoK can be used as a general target for anticancer drug design against Ras-dependent tumourigenesis.

Analysis of promazines in bovine livers by high performance liquid chromatography with ultraviolet and fluorimetric detection.

Fluorimetric and UV methods of detection for liquid chromatographic determination of phenothiazines (chlorpromazine, acetopromazine and propionylpromazine) were developed. The effects of several experimental parameters on the separation and the sensitivity of the methods were evaluated. The detection limits ranged from 31 to 350 ngml(-1). Optimized methods were successfully applied to determination of the promazines in bovine liver samples.