Metabolism encompasses the biochemical processes that allow healthy cells to keep energy, redox balance and building blocks required for cell development, survival, and proliferation steady. Malignant cells are well-documented to reprogram their metabolism and energy production networks to support rapid proliferation and survival in harsh conditions via mutations in oncogenes and inactivation of tumor suppressor genes. Despite the histologic and genetic heterogeneity of tumors, a common set of metabolic pathways sustain the high proliferation rates observed in cancer cells. This review with a focus on lung cancer covers several fundamental principles of the disturbed glucose metabolism, such as the “Warburg” effect, the importance of the glycolysis and its branching pathways, the unanticipated gluconeogenesis and mitochondrial metabolism. Furthermore, we highlight our current understanding of the disturbed glucose metabolism and how this might result in the development of new treatments.
Efficient fibre formation for all regioregular poly(3-alkylthiophene)s (P3ATs) with alkyl chain lengths (A) between 3 and 9 carbon atoms has been accomplished in several solvents. It was observed that for the aliphatic and (chlorinated) aromatic hydrocarbon solvents used, the solvent refractive index offers some rationale to predict the feasibility of a solvent for fibre formation. The fibres were separated from remaining non-organised polymer by centrifugation. This enabled the characterisation of the isolated fibres in function of alkyl chain length (A) with TEM, AFM, XRD and UV-Vis spectroscopy. The fibres are 20 ± 5 nm wide and 0.5 to >4 µm long and mainly crystallize in the common type I crystal phase. The order within the fibres was probed with XRD, SAED, and UV-Vis and was found to strongly improve with increasing alkyl chain length in going from P33T to P35T, resulting in a longer conjugation length. For P35T to P39T the improvement in order is only marginal. Fibres from P37T were found to mainly crystallize in a crystal phase slightly different from type I that we refer to as type I′. This new crystal structure has a lattice constant a that is marginally shorter than that of phase I and a slightly longer lattice constant b of 4.0 Å and thus in XRD can hardly be distinguished from phase I. It is furthermore characterized by a blue-shifted absorption band in UV-Vis spectroscopy. The type I′ fibres were converted into normal type I fibres in the solid state at 70 °C and in solution around 50 °C.
1 May 2007 in Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology
Lung cancer cells are well-documented to rewire their metabolism and energy production networks to support rapid survival and proliferation. This metabolic reorganization has been recognized as a hallmark of cancer. The increased uptake of glucose and the increased activity of the glycolytic pathway have been extensively described. However, over the past years, increasing evidence has shown that lung cancer cells also require glutamine to fulfill their metabolic needs. As a nitrogen source, glutamine contributes directly (or indirectly upon conversion to glutamate) to many anabolic processes in cancer, such as the biosynthesis of amino acids, nucleobases, and hexosamines. It plays also an important role in the redox homeostasis, and last but not least, upon conversion to α-ketoglutarate, glutamine is an energy and anaplerotic carbon source that replenishes tricarboxylic acid cycle intermediates. The latter is generally indicated as glutaminolysis. In this review, we explore the role of glutamine metabolism in lung cancer. Because lung cancer is the leading cause of cancer death with limited curative treatment options, we focus on the potential therapeutic approaches targeting the glutamine metabolism in cancer.