Biochim Biophys Acta Bioenerg
September 2018
Succinate is known to act as an inflammatory signal in classically activated macrophages through stabilization of HIF-1α leading to IL-1β production. Relevant to this, hypoxia is known to drive succinate accumulation and release into the extracellular milieu. The metabolic alterations associated with succinate release during inflammation and under hypoxia are poorly understood.
View Article and Find Full Text PDFIntratumoral hypoxia stimulates enrichment of breast cancer stem cells (BCSC), which are critical for metastasis and patient mortality. Here we report a metabolic adaptation that is required for hypoxia-induced BCSC enrichment and metastasis. Hypoxia-inducible factors coordinately regulate expression of genes encoding phosphoglycerate dehydrogenase (PHGDH) and five downstream enzymes in the serine synthesis pathway and mitochondrial one-carbon (folate) cycle.
View Article and Find Full Text PDFMammary epithelial cells transition between periods of proliferation and quiescence during development, menstrual cycles, and pregnancy, and as a result of oncogenic transformation. Utilizing an organotypic 3D tissue culture model coupled with quantitative metabolomics and proteomics, we identified significant differences in glutamate utilization between proliferating and quiescent cells. Relative to quiescent cells, proliferating cells catabolized more glutamate via transaminases to couple non-essential amino acid (NEAA) synthesis to α-ketoglutarate generation and tricarboxylic acid (TCA) cycle anaplerosis.
View Article and Find Full Text PDFBackground: Systematic quantitative methodologies are needed to understand the heterogeneity of cell metabolism across cell types in normal physiology, disease, and treatment. Metabolic flux analysis (MFA) can be used to infer steady state fluxes, but it does not apply for transient dynamics. Kinetic flux profiling (KFP) can be used in the context of transient dynamics, and it is the current gold standard.
View Article and Find Full Text PDFCancer cells adapt their metabolic processes to support rapid proliferation, but less is known about how cancer cells alter metabolism to promote cell survival in a poorly vascularized tumour microenvironment. Here we identify a key role for serine and glycine metabolism in the survival of brain cancer cells within the ischaemic zones of gliomas. In human glioblastoma multiforme, mitochondrial serine hydroxymethyltransferase (SHMT2) and glycine decarboxylase (GLDC) are highly expressed in the pseudopalisading cells that surround necrotic foci.
View Article and Find Full Text PDFWe report that a single growth factor, NM23-H1, enables serial passaging of both human ES and iPS cells in the absence of feeder cells, their conditioned media or bFGF in a fully defined xeno-free media on a novel defined, xeno-free surface. Stem cells cultured in this system show a gene expression pattern indicative of a more "naïve" state than stem cells grown in bFGF-based media. NM23-H1 and MUC1* growth factor receptor cooperate to control stem cell self-replication.
View Article and Find Full Text PDFMalignant brain cancer persists as a major disease of morbidity and mortality. The failure to recognize brain cancer as a disease of energy metabolism has contributed in large part to the failure in management. As long as brain tumor cells have access to glucose and glutamine, the disease will progress.
View Article and Find Full Text PDFMalignant brain tumors are a significant health problem in children and adults. Conventional therapeutic approaches have been largely unsuccessful in providing long-term management. As primarily a metabolic disease, malignant brain cancer can be managed through changes in metabolic environment.
View Article and Find Full Text PDFGBM (glioblastoma multiforme) is the most aggressive and invasive form of primary human brain cancer. We recently developed a novel brain cancer model in the inbred VM mouse strain that shares several characteristics with human GBM. Using bioluminescence imaging, we tested the efficacy of CR (calorie restriction) for its ability to reduce tumour size and invasion.
View Article and Find Full Text PDFMetastatic cancer is a major cause of morbidity and mortality. Current therapeutic options consist of chemotherapy, radiation or targeted therapies. However, these therapies are often toxic, effective over a small range of cancer types or result in drug resistance.
View Article and Find Full Text PDFEmerging evidence indicates that impaired cellular energy metabolism is the defining characteristic of nearly all cancers regardless of cellular or tissue origin. In contrast to normal cells, which derive most of their usable energy from oxidative phosphorylation, most cancer cells become heavily dependent on substrate level phosphorylation to meet energy demands. Evidence is reviewed supporting a general hypothesis that genomic instability and essentially all hallmarks of cancer, including aerobic glycolysis (Warburg effect), can be linked to impaired mitochondrial function and energy metabolism.
View Article and Find Full Text PDFWe recently identified a new tumor (VM-M3), which arose spontaneously in the brain of an inbred VM mouse. When grown outside the brain, the VM-M3 tumor expresses all major biological processes of metastasis to include local invasion, intravasation, immune system survival, extravasation, and secondary tumor formation involving lung, liver, kidney, spleen and brain. The VM-M3 tumor also expresses multiple properties of macrophage-like cells similar to those described previously in numerous human metastatic cancers suggesting that the VM-M3 model will be useful for studying most types of metastatic cancer, regardless of tissue origin.
View Article and Find Full Text PDFMetastasis is the process by which cancer cells disseminate from the primary neoplasm and invade surrounding tissue and distant organs, and is the primary cause of morbidity and mortality for cancer patients. Most conventional cancer therapies are ineffective in managing tumor metastasis. This has been due in large part to the absence of in vivo metastatic models that represent the full spectrum of metastatic disease.
View Article and Find Full Text PDFGangliosides are sialic acid-containing glycosphingolipids that have long been associated with tumor malignancy and metastasis. Mounting evidence suggests that gangliosides also modulate tumor angiogenesis. Tumor cells shed gangliosides into the microenvironment, which produces both autocrine and paracrine effects on tumor cells and tumor-associated host cells.
View Article and Find Full Text PDF