Glycolytic phenotype and AMP kinase modify the pathologic response of tumor xenografts to VEGF neutralization.

Abstract VEGF antagonists are now widely used cancer therapeutics, but predictive biomarkers of response or toxicity remain unavailable. In this study, we analyzed the effects of anti-VEGF therapy on tumor metabolism and therapeutic response by using an integrated set of imaging techniques, including bioluminescence metabolic imaging, 18-fluorodeoxyglucose positron emission tomography, and MRI imaging and spectroscopy. Our results revealed that anti-VEGF therapy caused a dramatic depletion of glucose and an exhaustion of ATP levels in tumors, although glucose uptake was maintained. These metabolic changes selectively accompanied the presence of large necrotic areas and partial tumor regress…

Protein profiles in human ovarian cancer cell lines correspond to their metabolic activity and to metabolic profiles of respective tumor xenografts

Many solid tumors show a large variability in glycolytic activity and lactate accumulation, which has been correlated with different metastatic spread, radioresistance and patient survival. To investigate potential differences in protein profiles underlying these metabolic variances, the highly glycolytic human ovarian cancer cell line OC316 was investigated and compared with the less glycolytic line IGROV-1. Extracellular acidification and oxygen consumption were analyzed with an extracellular flux analyzer. Glycolysis-associated proteins, including specific membrane transporters, were quantified through in-cell western analyses. Metabolic properties of corresponding tumor xenografts were …

The anti-oxidant capacity of tumour glycolysis.

In this mini-review data are summarised which provide evidence for the biological and clinical significance of tumour glycolysis and of its relationship to the redox state of cancer cells.Malignant transformation is associated with an overexpression of numerous glycolysis-related genes in the vast majority of human cancers. At the same time, glycolytic activity and glycolysis-linked metabolic milieu are often variable between individual tumours which induces large variations in treatment response and aggressiveness. Currently, there is no genetic or proteomic marker for the prediction of the therapeutic response for individual tumours, but the prognostic value of tumour lactate accumulation…

The expression level of the orphan nuclear receptor GCNF (germ cell nuclear factor) is critical for neuronal differentiation.

The germ cell nuclear factor (GCNF) is essential for normal embryonic development and gametogenesis. To test the prediction that GCNF is additionally required for neuronal differentiation, we used the mouse embryonal carcinoma cell line PCC7-Mz1, which represents an advantageous model to study neuronal cells from the stage of fate choice until the acquirement of functional competence. We generated stable transfectants that express gcnf sense or antisense RNA under the control of a tetracycline-regulated promoter. After retinoic acid-induced withdrawal from the cell cycle, sense clones developed a neuron network with changed properties, and the time course of neuron maturation was shortened.…

The expression level of GCNF affects fate choice during neural differentiation of PCC7 cells

The nuclear receptor GCNF (NR6A1) is required for embryonic survival and development, and regulation of fertility. We used a transgenic approach to investigate its role in neural differentiation. As model we chose the embryonal carcinoma cell line PCC7, which reproducibly differentiates into a tissue-like pattern of neuronal and non-neuronal cells after exposure to retinoic acid (RA). The differentiation pattern of gcnf sense and antisense clones consistently indicated that the expression level of GCNF positively correlated with the development of the neuronal fate. Moreover, antisense clones failed to down-regulate expression of the key regulator of differentiation Oct4 during the initial …

Localizing and Quantifying Metabolites In Situ with Luminometry: Induced Metabolic Bioluminescence Imaging (imBI)

A bioluminescence technique for quantitative and structure-associated imaging of pyruvate

A novel bioluminescence assay has been developed for measuring pyruvate within sections of snap-frozen tissue in a quantitative manner as well as with a spatial resolution on a microscopical level. The assay was verified via HPLC and two independent photometric tests. The novel assay makes it possible to determine pyruvate concentrations in cryosections in the range of 0-5.0 micromol/g tissue (dry weight). Based on the analysis of samples of given pyruvate concentrations, the assay exhibits a recovery with a deviationor =15%. The minimal detectable amount was 0.02 pmol based on a 20 microm thick tissue section with an area of 1 cm(2). Combination of the already established imaging biolumine…

Glycolytic metabolism and tumour response to fractionated irradiation.

Abstract Background and purpose To study whether pre-therapeutic lactate or pyruvate predict for tumour response to fractionated irradiation and to identify possible coherencies between intermediates of glycolysis and expression levels of selected proteins. Materials and methods Concentrations of lactate, pyruvate, glucose and ATP were quantified via bioluminescence imaging in tumour xenografts derived from 10 human head and neck squamous cell carcinoma (HNSCC) lines. Tumours were irradiated with 30 fractions within 6weeks. Expression levels of the selected proteins in tumours were measured at the mRNA and protein level. Tumour-infiltrating leucocytes were quantified after staining for CD45…

Hypoxia inducible factor-1alpha inactivation unveils a link between tumor cell metabolism and hypoxia-induced cell death.

Hypoxia and the acquisition of a glycolytic phenotype are intrinsic features of the tumor microenvironment. The hypoxia inducible factor-1alpha (HIF-1alpha) pathway is activated under hypoxic conditions and orchestrates a complex transcriptional program that enhances cell survival. Although the consequences of HIF-1alpha inactivation in cancer cells have been widely investigated, only a few studies have addressed the role of HIF-1alpha in the survival of cancer cells endowed with different glycolytic capacities. In this study, we investigated this aspect in ovarian cancer cells. Hypoxia-induced toxicity was increased in highly glycolytic cells compared with poorly glycolytic cells; it was a…