Current Medicinal Chemistry - Volume 24, Issue 28, 2017

Background: Pancreatic ductal adenocarcinoma (PDAC) is devastating. Because of its silent nature, the disease is often only diagnosed once it has reached an advanced, frequently inoperable stage. To date, we have no biomarkers that facilitate earlier diagnosis, leaving sufficient time for curative therapy that effectively lowers the very high mortality rate of this cancer entity. Because of this, the life expectancy of patients with PDAC is low (i.e. ≤ 6% five-year survival rates). New data, including particular genetic signatures and features of the stromal architecture of PDAC tumors, may better explain their aggressiveness, their relatively long-lasting painless expansion, and why chemotherapy so frequently fails. The typical tumor-induced stromal desmoplasia is characterized by cancer-associated fibroblasts (CAFs), decreased immune surveillance, cancer-associated neural remodeling, and a very low vascular density. This stromal microenvironment generates hypoxia, nutrient deficiency, immune suppression, and chemoresistance. The combination of factors results in a vicious disease that begins with the long-lasting, asymptomatic development of a large tumor mass, followed by a delayed diagnosis with a high percentage of inoperable states, exhibiting a poor response to all conservative therapeutic options, including radiation, and which ends with metastasis resulting in a rapid fatal outcome. Objective: In this article, we review coherences on genetic, cellular, immunological, Nano medical and stromal characteristics of PDAC tissue, and discuss metabolic abnormalities associated with and/or preceding the tumor progression rate. Conclusion: A more comprehensive understanding of the underlying mechanisms can improve the diagnostic and therapeutic management of patients suffering from this devastating type of cancer.

MAP kinase-interacting kinases (MNK1 and MNK2) are often activated downstream of ERK and p38 MAPK in the MAP kinase family. The role of MNKs in the development and progression of solid tumors and hematological malignancies has been widely discussed, particularly in the context of cap dependent translation, regulated by phosphorylation of eIF4E. MNK/eIF4E axis is involved in the expression of pro angiogenic, antiapoptotic, cell cycle, and motility proteins, such as MCL1, VEGF, MMP3, SNAIL, SMAD2, β-catenin or cyclin D1, and is essential during Ras and c Myc-induced transformation. MNK1/2 emerged as eligible targets for drug discovery in oncology, based on the antitumor effects observed in genetic knockout and RNA interference experiments and at the same time lack of adverse effects in dual knockout animals. There is a high interest in the development of pharmacological inhibitors of MNK1/2 as not only tools for further basic research studies but also potential drugs in diseases characterized by deregulated translation. Unfortunately, the role of MNK1/2 in cancer still remains elusive due to the absence of potent and selective probes. Moreover, in many instances, hypotheses have been built reliant upon unspecific MNK1/2 inhibitors such as CGP57380 or cercosporamide. Lately, the first two clinical programs targeting MNKs in oncology have been revealed (eFT508 and BAY 1143269), although several other MNK programs are currently running at the preclinical stage. This review aims to provide an overview of recent progress in the development of MNK inhibitors.

Phosphodiesterase (PDE) 4 is a superfamily of enzymes that catalyze the hydrolysis of cyclic adenosine 3',5'-monophosphate (cAMP), an intracellular second messenger and regulator of a wide array of genes and proteins. Increased levels of intracellular cAMP lead to activation of genes but also to inhibition of nuclear factor-kappa B, involved in pro-inflammatory responses. By increasing cAMP levels, PDE4 inhibitors, such as apremilast, reduced production of pro-inflammatory TNFα, IFNγ, and IL-17 and increased production of anti-inflammatory IL-10 in lipopolysaccharide-stimulated peripheral blood mononuclear cells, and in patients with psoriatic arthritis (PsA). Among PDE4 inhibitors, apremilast, roflumilast, and crisabolore have been approved for the treatment of psoriasis and PsA, chronic obstructive pulmonary disease, and atopic dermatitis, respectively. In a preliminary study on psoriasis and PsA we showed that at 6 months apremilast decreased IFNγ+CD3+ Th1 cells and IL- 17+CD3+ Th17 cells and increased regulatory B cells and regulatory T cells. In this review, we highlight recent findings of PDE4 inhibitors in atopic dermatitis, alopecia areata, uveitis, rheumatoid arthritis, psoriasis and PsA, systemic lupus erythematosus, vasculitis, systemic sclerosis, multiple sclerosis and inflammatory bowel disease. Given the role of cAMP as second messenger in diverse intracellular pathways, selective PDE4 inhibitors are likely to be therapeutic agents for various immune mediated diseases.

Osteonecrosis of the jaw (ONJ) is a rare treatment related side effect that was firstly described in 2002 through a case report in metastatic bone cancer patient treated with bisphosphonates (BPs) therapy. ONJ is defined as an eight weeks or longer clinical finding of exposed bone in the oral cavity without response to appropriate therapy. The diagnosis is mainly clinical but often requires a radiological confirmation with an orthopantomography. So it must be made by a dental specialist with sufficient experience on ONJ and requires a detailed anamnestic exploration of comorbidities and treatments history. In particular, ONJ affects a wide number of oncologic patients treated with BPs for bone metastatic cancers and, more recently, with anti-angiogenic drugs. The aim of this this paper is to describe diagnosis and classification of this rare but serious side effect and its pathophysiology. In particular, we provide a detailed description of clinical evidences upon the relationship between anti-angiogenic drugs and ONJ. Considering the evolving of cancer epidemiology with a greater number of cancer surviving patients, this side effect always deserves more attention. We conclude that ONJ must be always carefully investigated and prevented with a multidisciplinary approach involving oncologist, radiation oncologist and skilled dental practitioner when a cancer patient must begin a BP or an antiangiogenic treatment.

Background: Knowledge of molecular marker (typically protein or mRNA) expression in neural systems can provide insight to the chemical blueprint of signal processing and transmission, assist in tracking developmental or pathological progressions, and yield key information regarding potential medicinal targets. These markers are particularly relevant in the mammalian brain in the light of its unsurpassed cellular diversity. Accordingly, molecular expression profiling is rapidly becoming a major approach to classify neuron types. Despite a profusion of research, however, the biological functions of molecular markers commonly used to distinguish neuron types remain incompletely understood. Furthermore, most molecular markers of mammalian neuron types are also present in other organs, therefore complicating considerations of their potential pharmacological interactions. Objective: Here, we survey 15 prominent neurochemical markers from five categories, namely membrane transporters, calcium-binding proteins, neuropeptides, receptors, and extracellular matrix proteins, explaining their relation and relevance to synaptic communication. Method: For each marker, we summarize fundamental structural features, cellular functionality, distributions within and outside the brain, as well as known drug effectors and mechanisms of action. Conclusion: This essential primer thus links together the cellular complexity of the brain, the chemical properties of key molecular players in neurotransmission, and possible biomedical opportunities.

Diabetic retinopathy (DR) is a major diabetes complication and the leading cause for vision loss and blindness in the adult human population. Diabetes, being an endocrinological disorder dysregulates a number of hormonal systems including the renin angiotensin system (RAS), which thereby may damage both vascular and neuronal cells in the retina. Angiotensin II (Ang II), an active component of the RAS is increased in diabetic retina, and may play a significant role in neurovascular damage leading to the progression of DR. In this review article, we highlight the role of Ang II in the pathogenesis of retinal damage in diabetes and discuss a newly identified mechanism involving tissue chymase and angiotensin-(1-12) [Ang-(1-12)] pathways. We also discuss the therapeutic effects of potential RAS inhibitors targeting blockade of cellular Ang II formation to prevent/ protect the retinal damage. Thus, a better understanding of Ang II formation pathways in the diabetic retina will elucidate early molecular mechanism of vision loss. These concepts may provide a novel strategy for preventing and/or treating diabetic retinopathy, a leading cause of blindness worldwide.