Current Medicinal Chemistry - Volume 21, Issue 34, 2014

Evasion of apoptosis is an important reason for tumor cells to resist the anticancer drugs in cancer therapy. As a critical regulator, the inhibitor of apoptosis proteins (IAPs) can block the apoptosis by inhibiting the activities of caspases. Scientists find that IAPs are over-expressed in many cancer cells, such as leukemia and B-cell lymphoma, which elucidate that high levels of IAPs are closely related to tumorigenesis and cancer development. Thus, targeting IAPs may be an attractive strategy for anti-tumor treatment. As an endogenous antagonist of IAPs, second mitochondria-derived activator of caspases (Smac) can suppress their activities through directly binding to IAPs. Based on structural biology study, Smac interacts with IAPs through the Ala-Val-Pro-Ile (AVPI) tetra-peptide of Smac. Therefore, many agents have been studied to suppress the IAPs which result in the activation of caspases and subsequently induce the apoptosis of tumor cells based on mimicking AVPI peptide strategy. In this review, the functions of IAPs in apoptosis and the recent advance of IAPs antagonists will be discussed.

NF-ΚB is a significant transcription factor that regulates the expression of various pro-survival genes. IKK is a crucial protein kinase that activates NF-ΚB translocating from cytoplasm to nucleus for DNA binding. It is composed of three subunits, IKKα, IKKβ, IKKγ (NEMO), where IKKα and IKKβ are catalytic subunits, and IKKγ is the regulatory subunit. Many diseases, such as Hodgkin’s disease, Hepatitis-associated hepatocellular carcinoma, colorectal cancer, prostate cancer, rheumatoid arthritis and inflammatory bowel disease, are related to IKK and NF-ΚB. So far, various IKK inhibitors targeting the ATP binding site have been identified through high throughput screening, rational design or in silico methods, however, only three of them (CHS-828, EB-1627 and IMD-1041) have been under clinical studies, indicating the strategy for the design of IKK inhibitors need to be reinspected. Besides ATP-competitive inhibitors, several other inhibitors have also been disclosed recently, which provide novel concepts to the discovery of IKK inhibitors. In this review, we focus on two parts: 1) the chemotypes and binding patterns of the traditional ATP-competitive IKK inhibitors; 2) novel strategies for the identification of non-ATP-competitive IKK inhibitors as NF-ΚB modulators. Through these discussions we hope to present inspirations for the development of new IKK inhibitors.

The Adenosine A2A receptor is a member of the G-protein coupled receptor superfamily. It plays a key role in numerous physiological processes through the central nervous system and in peripheral tissues. Functional interactions between the A2A and dopamine D2 receptor has spurred interest in the use of antagonists as anti-Parkinson drugs. Additionally, oncology drugs are now being designed based on the potential for A2A antagonists to function as immunotherapeutics. From early studies based on classical xanthine type A2A antagonists through second generation agents, this mini review will cover aspects of the discovery, development, chemical synthesis and medicinal evaluation of this important class of drugs.

It has been clear that at least 1 billion adults worldwide are smokers and at least 700 million children are passive smokers at home. Smoking exerts a detrimental effect to many organ systems and is responsible for illnesses such as lung cancer, pneumonia, chronic obstructive pulmonary disease, cancer of head and neck, cancer of the urinary and gastrointestinal tract, periodontal disease, cataract and arthritis. Additionally, smoking is an important modifiable risk factor for the development of cardiovascular disease such as coronary artery disease, stable angina, acute coronary syndromes, sudden death, stroke, peripheral vascular disease, congestive heart failure, erectile dysfunction and aortic aneurysms via initiation and progression of atherosclerosis. A variety of studies has proved that cigarette smoking induces oxidative stress, vascular inflammation, platelet coagulation, vascular dysfunction and impairs serum lipid pro-file in both current and chronic smokers, active and passive smokers and results in detrimental effects on the cardiovascular system. The aim of this review is to depict the physical and biochemical properties of cigarette smoke and, furthermore, elucidate the main pathophysiological mechanisms of cigarette-induced atherosclerosis and overview the new therapeutic approaches for smoking cessation and augmentation of cardiovascular health.

Condrosulf® is a pharmaceutical formulation containing chondroitin sulfate (CS) as an active component possessing high quality and purity and standardized properties. CS is currently applied as a SYSADOA (Symptomatic Slow Acting Drug for Osteoarthritis) agent in Europe in the treatment of osteoarthritis (OA). Furthermore, Condrosulf® and pharmaceutical grade CS have also been proven to possess structure-modifying effects belonging to the S/DMOAD (structure/disease modifying anti-osteoarthritis drug) class. This review summarizes current knowledge on CS/Condrosulf® structure and its properties, its pharmacological activity as proved by many clinical trials and metaanalysis studies and focuses attention on its mechanisms of action in the pathophysiology of osteoarthritic joint tissues. Finally, future perspectives are discussed in connection with the possibility to apply new outcome measures, such as MRI and biomarkers, which can yield important advances in the use of Condrosulf® as well as the development of new drugs with different structures useful in particular for the treatment of inflammatory symptoms and able to retard the progression of arthritis.

The robust of fluorescent techniques to study the ligand-receptor interaction followed by rapidly developing fluorescence imaging techniques resulted in a burst of the novel fluorescent ligands development. Taking into consideration not only ligand’s high affinity to the receptor, but also their fluorescent properties to visualize the interaction even in the single cell level, gives the researchers a strong impulse to investigate that field of GPCR ligands. Moreover, paying attention to the “non pharmacological” advantages of these ligands, as well as the techniques to be used, fluorescent ligands become commonly used pharmacological tools to study GPCRs. Herein we report on the results described in the literature since late 2007 in the field of the fluorescent GPCR small, non-peptide ligands according the receptor affinity, fluorophores that has been used to tag the molecules and their fluorescent properties as well as their application in GPCR research.

Background: Patients with heart failure (HF) have a significant decline of renal function. We investigate the association between novel biomarkers of renal dysfunction and indices of inflammatory status and cardiac remodeling in patients with HF. Methods: We enrolled 79 consecutive patients with HF and 79 healthy subjects, adjusted for age and sex. Serum levels of neutrophil gelatinase-associated lipocalin (NGAL), cystatin-C, b-type natriuretic peptide (BNP), tumor necrosis factor alpha (TNFα) and matrix metalloproteinase-9 (MMP-9) were measured by ELISA. Creatinine clearance was estimated using Cockcroft-Gault formula (eCcl). Left ventricular ejection fraction was determined by echocardiography. Results: Patients with HF, compared to healthy subjects, had significantly higher NGAL (p=0.007) and cystatin-C levels (p=0.005). In HF patients, NGAL levels were positively correlated with Creatinine levels (r=0.40, p<0.001), TNFa levels (r=0.43, p<0.001), BNP levels (r=0.36, p=0.003), MMP-9 levels (r=0.37, p=0.02) and inversely correlated with left ventricle ejection fraction (r=-0.23, p=0.045). Interestingly, the association between NGAL and MMP-9 levels was independent from confounders such as age, gender, left ventricle ejection fraction, body mass index, TNFα levels, and BNP levels. Moreover, in HF patients, cystatin-C levels were inversely correlated with eCcl (r=-0.21, p=0.04). Cystatin-C levels were not correlated with TNFa, BNP, MMP-9 levels and with left ventricle ejection fraction (p=NS for all). Conclusions: NGAL is associated with left ventricle ejection fraction, and biomarkers of inflammation and cardiac remodeling in patients with HF. These findings highlight a possible common pathogenetic mechanism of renal dysfunction, inflammatory process and cardiac dysfunction in HF.