Current Medicinal Chemistry - Volume 23, Issue 22, 2016

Voltage-gated sodium channels (VGSC) are responsible for the selective influx of sodium ions in excitable cells. A number of physiological phenomena such as muscle contraction, pain sensation, processing of neuronal information in the brain as well as neuronal regulation of peripheral tissues rely on the activity of these channels. On the other hand, abnormal activity of VGSC are implicated in several pathological processes (e.g., cardiac arrhythmias, epilepsy, and chronic pain) which in some cases (e.g., channelopathies such as myotonias) are linked to specific gene mutations. As a result, VGSC have never stopped attracting the attention of medicinal chemists and the quest for novel drugs to treat these ion channels-associated diseases continues. In this review, VGSC blocking agents reported in the last lustrum are scrutinised with the aim to give a medicinal chemistry perspective on the most interesting compounds classified on the basis of (i) potential therapeutic application, (ii) targeted VGSC isoforms, and (iii) chemical scaffolds. Finally, the clinical potential of selected drug candidates from each chemotype is evaluated by comparing their ligand efficiency metrics. Possible routes for improvement of these preclinical candidates are also discussed.

A higher incidence of cancer has been observed in Human Immunodeficiency Virus (HIV) infected individuals as compared with healthy people of the same age. A complex relationship between HIV-induced immune suppression, chronic antigenic stimulation, and oncogenic virus co-infections may promote carcinogenesis and increase the risk of developing tumors in these patients. Cancers in HIV subjects include the AIDS-defining malignancies (ADMs) and other non-AIDS-defining malignancies (NADMs). Antiretroviral therapy has reduced the incidence of ADMs whereas a concurrent increase of NADMs was observed in the last years. Biomarkers are measurable parameters, characterizing normal or pathogenic processes, which could provide a high potential for risk evaluation and diagnosis of patients. Therefore, the early detection of cancer biomarkers in HIV-positive subjects would be useful to identify patients at most risk of tumor disease development. This review will focus principally on the risk assessment and diagnostic role of several biomarkers of malignancy in HIV patients including cellular and viral biomarkers, cytokines, immune activation molecules and genetic polymorphisms.

Background: The therapeutic properties of cannabinoids are well-known since ancient years. Growing evidence exist on endocannabinoid system (ECS) modulation related with human tumorigenesis. Objective: Taking into account the substantial role of ECS on immune cell regulation, the present review is aimed to summarize the emerging evidence concerning cannabinoid receptor (CBR) expression and cannabinoid ligand effects on haematological malignancies. Conclusions: Most of cannabinoid actions, mainly CB2R-mediated against haematopoietic malignant cells, seem promising, as inhibition of cell proliferation and apoptosis and paraptosis induction have been documented. Cannabinoid ligands appear to activate rudimentary pathways for cell survival, such as ERK, JNK, p38 MAPK, and to induce caspase synthesis, in vitro. Such data are strongly recommended to be confirmed by in vivo experiments with emphasis on cannabinoid ligands’ bioavailability and phytocannabinoid psychotropic properties. The preliminary antitumoral ECS effects and their relative lack of important side effects render ECS a promising therapeutic target for the treatment of haematological malignancies.

Skp2 is frequently overexpressed in many human cancers and plays a key role in tumorigenesis. As a component of the SCFSkp2 ubiquitin E3 ligase complex, Skp2 is responsible for recruiting substrate proteins for their ubiquitination and subsequent degradation by the 26S proteasome. Thus, Skp2 promotes the cell cycle by down-regulating cell cycle proteins such as the tumor suppressor p27. Alternatively, Skp2 suppresses p53-dependent apoptosis by outcompeting p53 for binding to p300, thereby perturbing p300-mediated p53 acetylation and stabilization. Taken together, inhibition of Skp2 functions (either proteolytic function or non-proteolytic function) is emerging as a promising and novel anti-cancer strategy. In the present review, we highlight the development of Skp2 inhibitors with different mechanisms of action.

Telomerase is a ribonucleoprotein enzyme, which has a significant role in synthesizing DNA telomeric in eukaryotes. Telomere maintenance can cause to immortalization and malignant transformation of human cells and thereby telomerase activity must be scrutinized as an important factor in most tumor cells. The proliferation of cancer cells or apoptosis induction can be suppressed by telomerase inhibition using different therapeutic agents without any side effects upon normal cells. Natural substances, with anti-tumor effects, such as those derived from plants can be suitable candidates due to their capabilities in preventing some side effects and resistance of tumors with respect to most chemotherapeutic drugs. In this regards, many studies have shown that natural phytochemicals have inhibitory effects on telomerase activity through affecting its subunits and components. Therefore, the aim of this paper is to review the recent studies on these kinds of phytochemicals in terms of property and mechanism. Moreover, strategies for improving the therapeutic efficacy of plant-derived substances such as combination therapy and nanoformulation based approaches are included.