Combinatorial antileukemic disruption of oxidative homeostasis and mitochondrial stability by the redox reactive thalidomide 2-(2,4-difluoro-phenyl)-4,5,6,7-tetrafluoro-1H-isoindole-1,3(2H)-dione (CPS49) and flavopiridol

Bioactive Lipids in Age-Related Disorders

Our own studies and those of others have shown that defects in essential fatty acid (EFA) metabolism occurs in age-related disorders such as obesity, type 2 diabetes mellitus, hypertension, atherosclerosis, coronary heart disease, immune dysfunction and cancer. It has been noted that in all these disorders there could occur a defect in the activities of desaturases, cyclo-oxygenase (COX), and lipoxygenase (LOX) enzymes leading to a decrease in the formation of their long-chain products gamma-linolenic acid (GLA), arachidonic acid, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). This leads to an increase in the production of pro-inflammatory prostaglandin E2 (PGE2), thromboxanes (TXs), and leukotrienes (LTs) and a decrease in anti-inflammatory lipoxin A4, resolvins, protectins and maresins. All these bioactive molecules are termed as bioactive lipids (BALs). This imbalance in the metabolites of EFAs leads to low-grade systemic inflammation and at times acute inflammatory events at specific local sites that trigger the development of various age-related disorders such as obesity, type 2 diabetes mellitus, hypertension, coronary heart disease, atherosclerosis, and immune dysfunction as seen in rheumatoid arthritis, lupus, nephritis and other localized inflammatory conditions. This evidence implies that methods designed to restore BALs to normal can prevent age-related disorders and enhance longevity and health.

Genetic susceptibility to thalidomide embryopathy in humans: Study of candidate development genes

Thalidomide is a drug used worldwide for several indications, but the molecular mechanisms of its teratogenic property are not fully understood. Studies in animal models suggest the oxidative stress, the inhibition of angiogenesis, and the binding to E3-ubiquitin ligase complex as mechanisms by which thalidomide can change the expression of genes important to embryonic development. In this study, seven polymorphisms in genes related to development (FGF8, FGF10, BMP4, SHH, TP53, TP63, and TP73) were analyzed in people with thalidomide embryopathy (TE) and compared to people without malformations. The sample consisted of 36 people with TE and 135 unrelated and nonsyndromic people who had their DNA genotyped by PCR real-time. Although no allelic or genotypic differences were observed between the groups, we hypothesized that other regions in these genes and related genes may play an important role in thalidomide teratogenesis, which is known to have a genetic contribution. Identifying such molecular mechanisms is essential for the development of a molecule that will be analogue to thalidomide but safe enough to avoid the emergence of new cases of TE.

Cancer drug resistance: redox resetting renders a way

Disruption of redox homeostasis is a crucial factor in the development of drug resistance, which is a major problem facing current cancer treatment. Compared with normal cells, tumor cells generally exhibit higher levels of reactive oxygen species (ROS), which can promote tumor progression and development. Upon drug treatment, some tumor cells can undergo a process of 'Redox Resetting' to acquire a new redox balance with higher levels of ROS accumulation and stronger antioxidant systems. Evidence has accumulated showing that the 'Redox Resetting' enables cancer cells to become resistant to anticancer drugs by multiple mechanisms, including increased rates of drug efflux, altered drug metabolism and drug targets, activated prosurvival pathways and inefficient induction of cell death. In this article, we provide insight into the role of 'Redox Resetting' on the emergence of drug resistance that may contribute to pharmacological modulation of resistance.

Mechanism of immunomodulatory drugs' action in the treatment of multiple myeloma

Although immunomodulatory drugs (IMiDs), such as thalidomide, lenalidomide, and pomalidomide, are widely used in the treatment of multiple myeloma (MM), the molecular mechanism of IMiDs' action is largely unknown. In this review, we will summarize recent advances in the application of IMiDs in MM cancer treatment as well as their effects on immunomodulatory activities, anti-angiogenic activities, intervention of cell surface adhesion molecules between myeloma cells and bone marrow stromal cells, anti-inflammatory activities, anti-proliferation, pro-apoptotic effects, cell cycle arrest, and inhibition of cell migration and metastasis. In addition, the potential IMiDs' target protein, IMiDs' target protein's functional role, and the potential molecular mechanisms of IMiDs resistance will be discussed. We wish, by presentation of our naive discussion, that this review article will facilitate further investigation in these fields.

Preformulation study of NSC-726796

A stability-indicating high-performance liquid chromatography method to quantify 2-(2,4-difluorophenyl)-4,5,6,7-tetrafluoroisoindoline-1,3-dione (NSC-726796) and its three main degradation products was developed. This method was used to investigate its degradation kinetics and mechanism. The reaction follows first-order kinetics and appears to be base catalyzed with the maximum stability at pH 1. The products were identified as 2-(2,4-difluorophenylcarbamoyl)-3,4,5,6-tetrafluorobenzoic acid (NSC-749820), 2,4-difluoroaniline, and tetrafluorophthalic acid. The parent drug, NSC-726796, was also found to react with methanol and ethanol. NSC-726796 demonstrates antiangiogenic activity, however, when its degradant NSC749820 does not show antiangiogenic activity.

MAP17 and the double-edged sword of ROS

Reactive oxygen species, ROS, are beneficially involved in many signaling pathways that control development and maintain cellular homeostasis. In physiological conditions, a tightly regulated redox balance protects cells from injurious ROS activity, but if the balance is altered, it promotes various pathological conditions including cancer. Understanding the duality of ROS as cytotoxic molecules and key mediators in signaling cascades may provide novel opportunities for improved cancer therapy. MAP17 is a small 17-kDa non-glycosylated membrane protein that is overexpressed in many tumors of different origins, including carcinomas. Immunohistochemical analysis of MAP17 during cancer progression demonstrates that overexpression of the protein strongly correlates with the progression of most types of tumor. Tumor cells that overexpress MAP17 show an increased tumoral phenotype associated with an increase in ROS. However, in non-tumor cells MAP17 increases ROS, resulting in senescence or apoptosis. Therefore, in tumor cells, MAP17 could be a marker for increased oxidative stress and could define new therapeutic approaches. Here, we review the role of MAP17 as a putative oncogene, as well as its role in cancer and anticancer therapies.

Redox stimulation of cardiomyogenesis versus inhibition of vasculogenesis upon treatment of mouse embryonic stem cells with thalidomide

Thalidomide [α-(N-phthalimido)-glutarimide] exerts antiangiogenic properties and causes cardiac malformations in embryos. Herein the effects of thalidomide on cardiovascular differentiation were investigated in mouse embryonic stem (ES) cell-derived embryoid bodies. Thalidomide inhibited the formation of capillary-like blood vessels and decreased tumor-induced angiogenesis in confrontation cultures of embryoid bodies and multicellular prostate tumor spheroids, but stimulated cardiomyogenesis of ES cells. The number of CD31- and CD144-positive endothelial cells was not impaired, suggesting that thalidomide acted on vascular tube formation and cell migration rather than endothelial differentiation. Thalidomide increased reactive oxygen species generation, which was abolished by the NADPH oxidase inhibitor VAS2870 and the complex I respiratory chain inhibitor rotenone. Conversely, thalidomide decreased nitric oxide (NO) generation and endothelial NO synthase activity. VAS2870 abrogated thalidomide stimulation of cardiomyogenesis, whereas inhibition of vasculogenesis persisted. In NOX-1 and NOX-4 shRNA gene-inactivated ES cells, cardiomyogenesis was severely impaired and thalidomide failed to stimulate cardiac cell commitment. The NO donor S-nitrosopenicillamine reversed the antiangiogenic effect of thalidomide and increased capillary structure formation, whereas scavenging NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and inhibition of endothelial NO synthase by N(G)-nitro-l-arginine methyl ester decreased cardiovascular differentiation. Our data demonstrate that thalidomide causes an imbalance of reactive oxygen species/NO generation, thus stimulating cardiomyogenesis and impairing vascular sprout formation.