Redox-active quinones and ascorbate: an innovative cancer therapy that exploits the vulnerability of cancer cells to oxidative stress

Cancer cells are particularly vulnerable to treatments impairing redox homeostasis. Reactive oxygen species (ROS) can indeed play an important role in the initiation and progression of cancer, and advanced stage tumors frequently exhibit high basal levels of ROS that stimulate cell proliferation and promote genetic instability. In addition, an inverse correlation between histological grade and antioxidant enzyme activities is frequently observed in human tumors, further supporting the existence of a redox dysregulation in cancer cells. This biochemical property can be exploited by using redox-modulating compounds, which represent an interesting approach to induce cancer cell death. Thus, we have developed a new strategy based on the use of pharmacologic concentrations of ascorbate and redox-active quinones. Ascorbate-driven quinone redox cycling leads to ROS formation and provoke an oxidative stress that preferentially kill cancer cells and spare healthy tissues. Cancer cell death occurs through necrosis and the underlying mechanism implies an energetic impairment (ATP depletion) that is likely due to glycolysis inhibition. Additional mechanisms that participate to cell death include calcium equilibrium impairment and oxidative cleavage of protein chaperone Hsp90. Given the low systemic toxicity of ascorbate and the impairment of crucial survival pathways when associated with redox-active quinones, these combinations could represent an original approach that could be combined to standard cancer therapy.

Transcriptomic analysis of aorta from a short-term high-fat diet fed mouse reveals changes in the expression of vessel structure genes

High-density microarrays were recently used to identify the genomic profiles of vascular cells during atherogenesis. This strategy succeeded in identifying both biomarkers and underlying biological processes of the pathological development. However, data documenting the early stages of disease are sparse. To identify the mechanisms involved in atherogenesis, we examined differential gene expression in the aorta of C57BL/6J mice fed a high-fat diet (HFD) or a low-fat diet (LFD), for a short period of time of three weeks. The cDNAmicroarray analysis revealed that the expression of 448 genes was significantly different between the two groups. As expected, key genes involved in lipid synthesis or catabolism were down- and upregulated, respectively, representing a normal gene expression response to increased cellular lipid levels. Overrepresented biological processes were identified by Gene Ontology (GO) analysis, which revealed that aortic cells differentiate into a new phenotype in mice fed the HFD. This phenotype was represented by changes in the expression of 81 genes associated with extracellular matrix and cytoskeletal modifications. Some of these genes were previously shown to be involved in the cardiovascular diseases process. In conclusion, short-term HFD consumption results in metabolic disturbances leading to a broad induction of genes involved in vessel architecture remodelling.

Plasma proteome analysis: 2D gels and chips

The knowledge of concentration, modification and interaction of proteins is fundamental in determining the phenotype of living organisms. Plasma, the primary clinical specimen, contains numerous and diverse proteins. The functions of these proteins are as manifold as the diversity of the protein themselves. Many of them have been largely used for many years as biomarkers of diseases and indicators of the physiological functions. The study of plasma proteome promises to be a significant advance in various areas of biological and clinical research. Two-dimensional polyacrylamide gel electrophoresis is considered as a primary tool in separating thousand of plasma proteins. This approach enables comparing normal and diseased samples revealing differently expressed proteins. Other proteomic techniques suitable for plasma analysis such as protein microarrays are now either established or are still being improved. This article briefly reviews the application of two-dimensional electrophoresis and the current status of technical aspects for plasma proteome.