Retinoblastoma treatment: impact of the glycolytic inhibitor 2-deoxy-d-glucose on molecular genomics expression in LHBETATAG retinal tumors

Purpose: The purpose of this study was to evaluate the effect of 2-deoxy-D-glucose (2-DG) on the spatial distribution of the genetic expression of key elements involved in angiogenesis, hypoxia, cellular metabolism, and apoptosis in LHBETATAG retinal tumors. Methods: The right eye of each LHBETATAG transgenic mouse (n = 24) was treated with either two or six subconjunctival injections of 2-DG (500 mg/kg) or saline control at 16 weeks of age. A gene expression array analysis was performed on five different intratumoral regions (apex, center, base, anterior-lateral, and posterior-lateral) using Affymetrix GeneChip Mouse Gene 1.0 ST arrays. To test for treatment effects of each probe within each region, a two-way analysis of variance was used. Results: Significant differences between treatment groups (ie, 0, 2, and 6 injections) were found as well as differences among the five retinal tumor regions evaluated (P \u3c 0.01). More than 100 genes were observed to be dysregulated by ≥2-fold difference in expression between the three treatment groups, and their dysregulation varied across the five regions assayed. Several genes involved in pathways important for tumor cell growth (ie, angiogenesis, hypoxia, cellular metabolism, and apoptosis) were identified. Conclusions: 2-DG was found to significantly alter the gene expression in LHBETATAG retinal tumor cells according to their location within the tumor as well as the treatment schedule. 2-DG’s effects on genetic expression found here correlate with previous reported results on varied processes involved in its in vitro and in vivo activity in inhibiting tumor cell growth

Antiangiogenic Activity of 2-Deoxy-D-Glucose

During tumor angiogenesis, endothelial cells (ECs) are engaged in a number of energy consuming biological processes, such as proliferation, migration, and capillary formation. Since glucose uptake and metabolism are increased to meet this energy need, the effects of the glycolytic inhibitor 2-deoxy-D-glucose (2-DG) on in vitro and in vivo angiogenesis were investigated.In cell culture, 2-DG inhibited EC growth, induced cytotoxicity, blocked migration, and inhibited actively forming but not established endothelial capillaries. Surprisingly, 2-DG was a better inhibitor of these EC properties than two more efficacious glycolytic inhibitors, 2-fluorodeoxy-D-glucose and oxamate. As an alternative to a glycolytic inhibitory mechanism, we considered 2-DG's ability to interfere with endothelial N-linked glycosylation. 2-DG's effects were reversed by mannose, an N-linked glycosylation precursor, and at relevant concentrations 2-DG also inhibited synthesis of the lipid linked oligosaccharide (LLO) N-glycosylation donor in a mannose-reversible manner. Inhibition of LLO synthesis activated the unfolded protein response (UPR), which resulted in induction of GADD153/CHOP and EC apoptosis (TUNEL assay). Thus, 2-DG's effects on ECs appeared primarily due to inhibition of LLOs synthesis, not glycolysis. 2-DG was then evaluated in two mouse models, inhibiting angiogenesis in both the matrigel plug assay and the LH(BETA)T(AG) transgenic retinoblastoma model.In conclusion, 2-DG inhibits endothelial cell angiogenesis in vitro and in vivo, at concentrations below those affecting tumor cells directly, most likely by interfering with N-linked glycosylation rather than glycolysis. Our data underscore the importance of glucose metabolism on neovascularization, and demonstrate a novel approach for anti-angiogenic strategies

Ultraviolet Light-Induced Unscheduled Dna Synthesis In Isolated Myocardial Cells From Different Aged Rats

Technik von gestern für die Ziele von morgen? : energiepolit. Orientierungen auf d. Weg zur postmaterialist. Ges. / Walter Molt ... (Hrsg.). - Opladen : Westdt. Verl., 1986. - 153 S

Interferon Inhibits Cardiac Cell Function in Vitro

Abstract Interferon which has been shown to exert important effects on cellular function was utilized to investigate its effect on cardiac cell beating in vitro. When steadily pulsating rat cardiac cultures were continuously exposed to rat interferon for 24 hr, a decrease in the beating rate was observed. Mouse interferon which also exerted antiviral activity on rat heart nonmuscle cells also decreased the beating rate of rat cardiac cultures. Human leukocyte interferon when tested at the same dose at which rat interferon was active, exhibited no antiviral activity in rat heart nonmuscle cells and did not exert beating rate effects. When mouse interferon was incubated with antiserum prepared against mouse interferon both antiviral and beating activity were neutralized to the same extent. None of the interferons used produced morphological effects on the heart cells and with rat interferon the beating rate effect was reversible. This finding, that interferon affects cardiac cell function in vitro, may have relevance to clinical application

8 - Effects of Creatine Phosphate on Cultured Cardiac Cells

This chapter discusses the effects of creatine phosphate on cultured cardiac cells. Cardiac muscle cells are unique in that they maintain their ability to beat in culture for prolonged periods. The beating of the cells is both characteristic of and dependent upon their environment, which can be rigorously controlled by the culture medium. Thus, if the medium is made hypoxic, the cells stop beating. The response to such an intervention is used as a model of the whole organ under similar conditions. It reports that cardiac cells growing in culture are not irreversibly damaged by prolonged exposure to 100% CO2. The addition of exogenous creatine phosphate (PCr) does not alter the arrhythmic effect produced by 100% CO2 treatment or the arrest or recovery times. Since intracellular PCr is known to be lowered in adriamycin (ADM) treated hearts, as well as other pathological muscle tissues, it is possible that the addition of this compound exogenously restores some minimal level necessary for beating. The chapter also focuses on whether PCr may have clinical application in patients treated with ADM