76 research outputs found
Abstract 62: Alteration of metabolic pathways of glucose consumption by CENU treatment in B16 melanoma tumors: A NMR spectroscopy-based [1,2-13C]glucose fluxomics analysis
No full textAbstract
We have previously shown using proton NMR spectroscopy-based metabolomics that mice bearing B16 melanoma tumors treated by chloroethylnitrosourea (CENU) had a strong intratumoral decrease in glycolysis involving the accumulation of intracellular glucose and glucose-6-phosphate, together the accumulation of glutamate derivatives, despite no significant lactate content change (1).
To get insights into the metabolic pathway followed by glucose carbons in CENU-treated tumor, we used double labelled glucose ([1,2-13C]glucose) and investigated the obtained isotopomers of lactate, the final product of glycolysis. Mice bearing B16 melanoma tumors were treated by CENU or saline solution (control) at days 11, 14 and 17 at dose 15µg/g weight. At day 23, mice were injected intraperitoneally with [1,2-13C]glucose at 25 mg in 150µl saline solution. Animals were sacrificed 30 minutes after glucose injection. Tumors were removed and kept at −80°C until use. The analysis of lactate isotopomers, a fluxomics approach, was done at 500 MHz using high resolution magic angle spinning (HRMAS) 1H-NMR spectroscopy by exploiting 1H-13C coupling signals. The two lactate signals, the methyl (C3) signal centered at 1.33 ppm and the methine (C2) signal centered at 4.12 ppm were differentially analyzed, and quantified from spectra witout and with broadband 13C-decoupling. In addition, the activity of pyruvate-kinase was measured using enzyme assay.
In comparison with control tumors, CENU-treated tumors exhibited an overall decrease of labelled lactate both at C3 and C2 position, together with a significant increase in the relative proportion of C2 to C3 labelling (0.65±0.10 vs 0.91±0.13, P<0.01, n=3 vs n=3). Because lactate only labelled on C3 was a product of glucose metabolism through the pentose phosphate pathway, it was concluded that most of glucose in CENU-treated tumors was directly metabolized to lactate, thus dedicated to ATP production rather than macromolecular biosynthesis. Consistently, the activity of pyruvate kinase, the main source of glycolysis-derived ATP was increased under CENU treatment (+48%, P<0.01).
Altogether these fluxomics data provide evidence of glycolysis adaptation that may be correlated to reduced proliferation, decreased aggressiveness, and redifferentiation, as previously shown in this model (2). In addition, this study suggests that metabolic targeting of glycolysis-related ATP production may improve CENU efficacy.
1- Morvan D, Demidem A. Cancer Res, 67; 2150-59, 2007
2- Demidem A et al. Cancer Res, 61; 2294-300, 2001
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 62.</jats:p
NMR metabolomics of fibroblasts with inherited mitochondrial Complex I mutation reveals treatment-reversible lipid and amino acid metabolism alterations
No full textInternational audienceIntroduction Elucidating molecular alterations due to mitochondrial Complex I (CI) mutations may help to understand CI deficiency (CID), not only in mitochondriopathies but also as it is caused by drugs or associated to many diseases. Objectives CID metabolic expression was investigated in Leber's hereditary optic neuropathy (LHON) caused by an inherited mutation of CI. Methods NMR-based metabolomics analysis was performed in intact skin fibroblasts from LHON patients. It used several datasets: one-dimensional H-1-NMR spectra, two-dimensional H-1-NMR spectra and quantified metabolites. Spectra were analysed using orthogonal partial least squares-discriminant analysis (OPLS-DA), and quantified metabolites using univariate statistics. The response to idebenone (IDE) and resveratrol (RSV), two agents improving CI activity and mitochondrial functions was evaluated. Results LHON fibroblasts had decreased CI activity (-43%, p 1 in OPLS-DA, p 1) and alanine (VIP > 1, p 1 and/or p < 0.05). Conclusion LHON fibroblasts display lipid and amino acid metabolism alterations that are reversed by mitochondria-targeted treatments, and can be related to adaptive changes. Findings bring insights into molecular changes induced by CI mutation and, beyond, CID of other origins
Bystander effects are induced by CENU treatment and associated with altered protein secretory activity of treated tumor cells A relay for chemotherapy?
No full textCalendarium naturale magicum perpetuum profundissimam rerum secretissimarum contemplationem totiusque Philosophiæ cognitionem complectens [graphic].
No full textThe print depicts and describes a hermetic universe, with fourteen horizontal parts, each subdivided vertically into a number of sections connecting with others. The print incorporates alchemical, astrological and mystical elements.Ref.: Magic, alchemy and science 15th-18th centuries : the influence of Hermes Trismegistus, ed. Carlos Gilly, Cis van Heertum. Florence: Centro Di, 2002; The magical calendar: a synthesis of magical symbolism from the seventeenth century renaissance of medieval occultism, ed. Adam McLean. Edinburgh: Magnum Opus, Hermetic Sourceworks, 1979.Cf. Gilly: the reference to Tycho Brahe as inventor implies only that the Calendarium imitates the method employed by the Danish astronomer.Print lacking date, attributed to Matthaeus Merian after images and text by Johann Baptist Grossschedel von Aicha.Print with letters: Auth. Iohan Babtista [Gro]ssschedel ab Aicha; Io. Theodore de Bry excudeb.; Thico Brahae inuentor 1582.Three sheets joined on linen mount.The print depicts and describes a hermetic universe, with fourteen horizontal parts, each subdivided vertically into a number of sections connecting with others. The print incorporates alchemical, astrological and mystical elements.Mode of access: Internet.mlanAssessed: Condition report in research file
Combined methionine deprivation and chloroethylnitrosourea have time-dependent therapeutic synergy on melanoma tumors that NMR spectroscopy-based metabolomics explains by methionine and phospholipid metabolism reprogramming
No full textInternational audienceMethionine (Met) deprivation stress (MDS) is proposed in association with chemotherapy in the treatment of some cancers. A synergistic effect of this combination is generally acknowledged. However, little is known on the mechanism of the response to this therapeutic strategy. A model of B16 melanoma tumor in vivo was treated by MDS alone and in combination with chloroethylnitrosourea (CENU). It was applied recent developments in proton-NMR spectroscopy-based metabolomics for providing information on the metabolic response of tumors to MDS and combination with chemotherapy. MDS inhibited tumor growth during the deprivation period and growth resumption thereafter. The combination of MDS with CENU induced an effective time-dependent synergy on growth inhibition. Metabolite profiling during MDS showed a decreased Met content (P < 0.01) despite the preservation of the protein content, disorders in sulfur-containing amino acids, glutamine/proline, and phospholipid metabolism [increase of glycerophosphorylcholine (P < 0.01), decrease in phosphocholine (P < 0.05)]. The metabolic profile of MDS combined with CENU and ANOVA analysis revealed the implication of Met and phospholipid metabolism in the observed synergy, which may be interpreted as a Met-sparing metabolic reprogramming of tumors. It follows that combination therapy of MDS with CENU seems to intensif
Lympho-epidermal Interactions in Patients Receiving Human Langerhans cell Free Cultured Epidermal Allografts as a Skin Substitute
No full textCD4 Antibody Therapy and Cyclosporin A Differentially Affect HLA-DR and ICAM-1 Expression in Psoriatic Skin
No full textParatext as Moral-Ethical Orientation in Harriet Jacobs's <i>Incidents in the Life of a Slave Girl </i>(1861)
No full textIn the preface to her autobiography, Incidents in the Life of a Slave Girl, Written by Herself (1861), Harriet Jacobs makes explicit her “desire to arouse the women of the North to a realizing sense of the condition” of enslaved people (Jacobs n. pag.). The preface itself constructs an implied reader and gears their moral judgement towards condemning slavery. As is characteristic of the autobiographical genre, Jacobs’s narrative identifies her simultaneously as author, narrator, and protagonist. Thus, her “Preface by the Author” blurs the distinction between her textual status as narrator and her extratextual status as author. This conflation is key to constructing the implied reader of the narrative: the narrator does not address mere narratees but constructs the latter as real-life readers – women living in the Northern US – whose reading experience, the preface claims, could prompt a real-life sense of personal responsibility in the struggle against slavery. The rhetoric of the preface can be analyzed through the combined lenses of deictic theory and narrative ethics. Jacobs’s moral-ethical deixis includes markers like right/wrong, good/bad and true/false. Jacobs orients the implied reader towards Abolition, by instructing them to judge “Freedom” as good and “Slavery” as bad. Correspondingly, Jacobs associates slavery with “persecut[ion]” and “suffering” by presenting it as a “deep, and dark, and foul ... pit of abominations” (Jacobs n. pag.). This moral deictic system is solidified by Jacobs’s claim, as author-narrator, that to validate these ethical coordinates is to “realiz[e]” the truth (Jacobs n. pag.). The moral deixis of Jacobs’s preface is instrumental in constructing what James Phelan defines as “the ethics of the telling” and “the ethics of reading/reception” of the narrative (Phelan n. pag.). The invitation of the implied audience into Jacobs’s ethical perspective simultaneously assigns them “moral responsibilities” and “obligations” (Phelan n. pag.) vis-à-vis the diegesis and its narratio
Comparison of Effects of Transforming Growth Factor-Beta and Cyclosporin A on Antigen-Presenting Cells of Blood and Epidermis
No full textThe antigen-processing and -presenting functions of freshly obtained epidermal Langerhans cells (fresh LC) and 72-h Cultured Langerhans cells (cultured LC) differ remarkably. It as been proposed that the disparate functional programs revealed in vitro may correspond directly with distinct in vivo physiologic functions—fresh LC are the in vitro equivalent of intraepidermal LC and cultured LC are equivalent to LC that have migrated from skin to the draining lymph node. As an approach to studying this proposal, we have compared the effects of two immunosuppressive agents, cyclosporin A (CsA) and transforming growth factor-beta (TGFβ), on the alloantigen-presenting capabilities of fresh LC, cultured LC, and peripheral blood mononuclear cells (PBMC). CsA pretreatment (1 and 10 μ/ml × 2 h) profoundly inhibited alloantigen presentation by fresh LC, cultured LC, and PBMC. By contrast, TGFβ pretreatment (1 and 10 ng/ml × 2 h) inhibited presentation by PBMC and cultured LC, but not by fresh LC. The resistance of fresh LC to the deleterious effects of TGFβ is discussed in terms of the possibility that TGFβ may inhibit antigen processing following conventional endocytosis. We suggest that fresh, but not cultured, LC escape TGFβ effects because they possess an “alternative” endocytic pathway, marked by the presence of Birbeck granules
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