Current Medicinal Chemistry - Volume 22, Issue 17, 2015

Amyotrophic lateral sclerosis (ALS) is a fatal disease caused by the gradual degeneration and death of upper and lower motor neurons. Despite continue efforts, the etiology and pathogenesis of ALS are not well understood yet. The lack of knowledge about molecular and cellular players involved in the neurodegenerative progression of ALS hinders effective therapy development. Several genomicbased studies have been conducted to identify genetic contributors to sporadic ALS (SALS) and new potential pharmacological targets, but these have resulted in short and non-overlapping lists of candidates. In the last few years, our research group has developed the largest whole-genome expression profile database of SALS human samples. We have identified several genes deregulated in the motor cortex of SALS patients and analyzed the role of these genes within deregulated pathways, providing a full molecular portrait of ALS pathogenesis. Some of deregulated genes encode for proteins that are direct or indirect targets of experimental or therapeutic drugs already applied to unrelated diseases. In this review, we focus on the potential role of candidate targets in ALS pathophysiology, highlighting their possible contribution to ALS therapy. The rational selection of the most promising drug targets and related modulatory drugs may provide a starting point for their preclinical or clinical validation and, hopefully, the development of more effective treatments for ALS patients.

This review focuses on the application of click chemistry in medicinal sciences, and particularly on its role in drug discovery. Because of its high modularity, click chemistry helps to accelerate the current drug discovery process, which relies on massive screening of chemical libraries. This article describes examples of click chemistry applications that are aimed at finding new lead candidates against pathologies such as cancer, AIDS and Alzheimer’s disease, and explores the impact that the technique could have in therapy and prevention in the near future, through application in drug delivery systems, bioconjugation and diagnostic. An introduction, addressed to researchers who intend to use this methodology, examines the opportunities to perform click reactions according to the most common and best studied techniques, such as synthesis in water, on solid phase, and under microwave or ultrasound irradiation. Every topic is furnished with examples which have appeared in the literature in the last five years and is clarified by schemes and figures.

Epigenetics, the study of heritable changes in gene expression without modifying the nucleotide sequence, is among the most important topics in medicinal chemistry and cancer prevention and therapy. Among those changes, DNA methylation and histone modification have been shown to be associated with various types of cancers in a number of ways, many of which are regulated by dietary components that are mostly found in plants. Although mechanisms of nutrient components affecting histone acetylation/deacetylation in cancer are widely studied, how those natural compounds affect cancer through other histone modifications, such as methylation, phosphorylation and ubiquitylation, is rarely reviewed. Thus, this review article discusses impacts on histone acetylation as well as other histone modifications by nutrient components, such as genistein, resveratrol, curcumin, epigallocatechin-3-gallate (EGCG), 3,3’-diindolylmethane (DIM), diallyl disulfide, garcinol, procyanidin B3, quercetin, sulforaphane and other isothiocyanates that have been recently reported in vivo as well as in various types of cancer cell lines.

Leukemia is a life threatening disease that has become increasingly common. Many categories of anti-leukemic agents have been developed by probing into the nature of leukemia. Nevertheless, the needs for potent molecules with few side effects are still not satisfied in the current anti-leukemic therapy. Targeted therapy has been developed for the advantage of relatively high efficiency and safety in the anticancer chemotherapy. Among the targeted antitumor therapies, inhibition of histone deacetylases has been intensively studied. Three histone deacetylase inhibitors (HDACIs) have been approved by US Food and Drug administration (FDA) for the treatment of cancer. Interestingly, a number of HDACIs selectively exhibited inhibitory effects on leukemic cell lines in the preclinical researches. Herein, the anti-leukemic HDACIs were reviewed to gain insight into HDACIs’ potential as anti-leukemic agents.

Epigenetic dysregulation has been recognized as an important contributor to cancer initiation and progression as most tumors harbor both genetic and epigenetic abnormalities. Inhibiting epigenetic proteins represents a novel approach in cancer drug discovery and more profound efficacy and less resistance are expected since multiple signaling pathways can be modulated as a result of inhibiting a single epigenetic target. Histone methyl transferases (HMTs) are an important component in epigenome and HMT inhibitors are being pursued intensely by both pharmaceutical industry and academic institutions. In this article we will provide an update on the drug discovery effort on several key HMTs.

Histamine and histamine receptors are well known for their immunomodulatory role in inflammation. In this review we describe the role of histamine and histamine H4 receptor on human eosinophils. In the first part of article we provide short summary of histamine and histamine receptors role in physiology and histamine related therapeutics used in clinics. We briefly describe the human histamine receptor H4 and its ligands, as well as human eosinophils. In the second part of the review we provide detailed description of known histamine effects on eosinophils including: intracellular calcium concentration flux, actin polymerization, cellular shape change, upregulation of adhesion proteins and cellular chemotaxis. We provide proofs that these effects are mainly connected with the activation of histamine H4 receptor. When examining experimental data we discuss the controversial results and limitations of the studies performed on isolated eosinophils. In conclusion we believe that studies on histamine H4 receptor on human eosinophils can provide interesting new biomarkers that can be used in clinical studies of histamine receptors, that in future might result in the development of new strategies in the treatment of chronic inflammatory conditions like asthma or allergy, in which eosinophils are involved.

The nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase, NOX) enzyme family catalyzes the production of reactive oxygen species (ROS). ROS have functional roles in cell cycling and signal transduction but their excessive production results in oxidative stress which is believed to have pathological consequences. Oxidative stress in the intestinal tract is considered a major factor contributing to the pathogenesis and progression of inflammatory bowel disease (IBD), as recent data suggest a positive correlation between upregulated NOX and gastrointestinal inflammation. Moreover, expression of certain NOX gene variants has been shown to affect the susceptibility of an individual to develop IBD. As current treatments for IBD are not entirely effective, the pharmacological inhibition of NOX is an unexplored avenue that could provide a potential therapeutic target for the treatment of this disease.