Current Drug Targets - Volume 15, Issue 12, 2014

Plasmodium falciparum is one of the deadliest protozoan parasite species among those that cause malaria. Uncontrolled use of antimalarial drugs has resulted in evolutionary selection pressure favoring high levels of resistance to antimalarials; currently P.falciparum shows resistance to all classes of antimalarials. Therefore it is essential to identify novel drug targets, and design selective anti-malarials which can overcome resistance. While many drug targets are freely available in various public domain resources, a single comprehensive source of data containing easily searchable and retrievable information is currently lacking. To facilitate the total integration and mining of data emerging from different drug consortia and also to prioritize drug targets for structure-based drug design, an open-access, inclusive comprehensive database for Plasmodium falciparum was established. Meta data of known/modeled structures along with binding site parameters of drug targets have been included in the database. Additionally, chemical compounds showing a positive inhibitory assay against Plasmodium falciparum or known drug targets have also been provided. The database is accessible at http://pfaldb.jnu.ac.in. The database provides diverse information regarding the structure, sequence, stage specific gene expression, pathway, action mechanism, essentiality and druggability for each drug target, and literature to assess the validation status of individual drug targets. It also includes information on individual anti-malarials with their activity and bioassay.

Post-translational modifications (PTMs) play important roles in regulating protein stability, trafficking, folding conformation, and functional activity. Small ubiquitin-like modifier (SUMO) protein mediates a distinct type of PTM called SUMOylation in which the SUMO protein is covalently ligated to the target protein and modifies its activities through a series of enzymatically-catalyzed reactions. SUMOylation regulates many cellular processes like transcription, the maintenance of the ion gradient across the cell membrane, stress response, autoimmunity, etc. Several target proteins of SUMOylation are involved in the biological pathways related to various human diseases, including cardiovascular diseases, diabetes, cancer, and neurodegenerative disorders. This review focuses on the SUMOylation process, regulatory roles of SUMOylation in diabetes, and prospects of developing novel anti-diabetic drugs targeting the SUMOylation process.

According to international guidelines, treatment of cervical cancer (CC) consists of surgery in early stages and of chemoradiation in locally advanced disease. Metastatic disease is usually treated with palliative chemotherapeutic regimens, but cytostatic drugs present significant side effects and show limited activity. Thus, the discovery of new anticancer agents, interfering with molecular targets expressed by the tumor’s microenvironment or by the tumor cell itself, represents a possible chance for the struggle against this tumor. The aim of this review is to report all targets that have been investigated in preclinical and clinical studies. We discuss these potential targets according to “targeted therapies” NCI classification. The most investigated molecular targets have been epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF), both involved in CC etiopathogenesis. Studies with anti-angiogenetic agents showed encouraging clinical efficacy and acceptable toxicity. Other interesting results have been obtained by immunotherapeutic strategies. Since biological characteristics of CC, especially in recurrent disease, are still partially unknown, future studies are necessary to understand mechanisms involved in CC carcinogenesis, in order to give to patients the most tailored and efficient treatments.

This review presents and discusses the current status and perspectives of leishmaniasis treatment, with a special focus on the use of proteinase inhibitors. The history of treatment development, the first- and second-choice modern drugs and the advantages and disadvantages of using proteinases inhibitors as leishmanicidal treatments are presented and discussed. The reports gathered herein confirm the potential usefulness of proteinases inhibitors as an alternative or complement to the current leishmaniasis treatments. They also support the hypothesis that a combined treatment with multiple proteinase inhibitors may be efficient against Leishmania infections in vertebrate hosts.

Antibiotics remain the mainstay of treatment for infectious diseases, but the growing frequency of antibiotic resistance represents a major concern for healthcare worldwide. The use of antibiotics in recurrent infections raises other issues, such as their limitations for treating diverse microorganisms, deleterious effects on the microbiota of the patient and potential adverse effects. In recent years, progress has been made towards the development of novel polybacterial vaccines administered via the mucosal route. These drugs target both the innate and adaptive immune systems, at the actual point of entry of most pathogens. In addition to boosting immune responses, mucosal bacterial vaccines have an intriguing immunomodulatory activity that does not compromise their efficacy against infectious agents. We review here the current clinical evidence concerning the efficacy and safety of these mucosal vaccines for the prevention and treatment of recurrent infection. We also provide an overview completing the landscape of the potential clinical uses of these active biological agents.

Malaria is a devastating human parasitic disease that receives enhanced attention due to the emergence of resistance to traditional drugs. Thus, the search for new molecular targets is a major goal. PfAM1 is an aminopeptidase from Plasmodium falciparum, William H. Welch 1897, belonging to the M1 family of metalloproteases, which is a promising target of inhibitors to block the intra-erythrocytic stages of the parasite. Since its identification in 1998, many efforts have been done to validate PfAM1 as an appropriate target of antimalarials. The present work is a critical review of the main structural, functional and kinetic characteristics of PfAM1, as well as a summary of the effects of key inhibitors at molecular and cellular levels. The systematization of experimental results should contribute to a better understanding of the properties of PfAM1 as a target of antimalarials and promote research projects focused on the development of PfAM1 inhibitors.

Background: Breast cancer (BC), the most frequent malignancy in women worldwide, is currently diagnosed in about 1.4 million female patients annually. Approximately 10-20% of BC is represented by triple negative breast cancer (TNBC) which is aggressive, the prognosis is poor and patients cannot benefit from targeted treatment based on hormonal or HER2 receptors. For this reason, search for markers that can predict the efficacy of chemotherapy in TNBC is a priority. Methods and Results: This review focuses on BCL2 protein as a prognostic marker in TNBC and its potential as a predictor of sensitivity to chemotherapy. Conclusion: BCL2 protein expression is a positive prognostic factor in BC. Better survival of patients with BCL2 positivity (BCL2+) has been explained by the correlation with estrogen receptor positive (ER+) status. BCL2+ is however not simply a surrogate marker for ER+. Moreover, BCL2 protein expression is also a positive prognostic marker in the TNBC subgroup. We and others show, that low BCL2 expression was associated with good outcome of TNBC patients treated with both adjuvant and neoadjuvant anthracycline-based chemotherapy. On the other hand, recent studies have shown that a subset of TNBC patients may benefit from the classical adjuvant CMF (cyclophosphamide, methotrexate, 5-fluorouracil) regimen. Given the heterogeneity of TNBC there is an urgent need to find and validate the sensitivity predictors to these regimens making them usable in clinical practice. BCL2 enrichment has been described in the mesenchymal stem-like (MSL) TNBC subgroup.