Methylene blue inhibits lumefantrine-resistant Plasmodium berghei.

J Infect Dev Ctries. 2016;10(6):635-642

Authors: Mwangi VI, Mumo RM, Kiboi DM, Omar SA, Ng'ang'a ZW, Ozwara HS

Abstract
INTRODUCTION: Chemotherapy still is the most effective way to control malaria, a major public health problem in sub-Saharan Africa. The large-scale use of the combination therapy artemether-lumefantrine for malaria treatment in Africa predisposes lumefantrine to emergence of resistance. There is need to identify drugs that can be used as substitutes to lumefantrine for use in combination therapy. Methylene blue, a synthetic anti-methemoglobinemia drug, has been shown to contain antimalarial properties, making it a candidate for drug repurposing. The present study sought to determine antiplasmodial effects of methylene blue against lumefantrine- and pyrimethamine-resistant strains of P. berghei.
METHODOLOGY: Activity of methylene blue was assessed using the classical four-day test on mice infected with lumefantrine-resistant and pyrimethamine-resistant P. berghei. A dose of 45 mg/kg/day was effective for testing ED90. Parasitemia and mice survival was determined.
RESULTS: At 45 mg/kg/day, methylene blue sustained significant parasite inhibition, over 99%, for at least 6 days post-treatment against lumefantrine-resistant and pyrimethamine-resistant P. berghei (p = 0.0086 and p = 0.0191, respectively). No serious adverse effects were observed.
CONCLUSIONS: Our results indicate that methylene blue at a concentration of 45 mg/kg/day confers over 99% inhibition against lumefantrine- and pyrimethamine-resistant P. berghei for six days. This shows the potential use methylene blue in the development of antimalarials against lumefantrine- and pyrimethamine-resistant parasites.

PMID: 27367013 [PubMed - as supplied by publisher]

Drug repositioning approaches to parasitic diseases: a medicinal chemistry perspective.

Drug Discov Today. 2016 Jun 27;

Authors: Ferreira LG, Andricopulo AD

Abstract
Identifying new indications for clinically useful drugs is a worthwhile approach for neglected tropical diseases. The number of successful repurposing cases in the field is growing as not-for-profit organizations, in association with academia and pharmaceutical companies, enable screening campaigns for the identification of new repositioning candidates. Current programs have delivered encouraging results as the use of state-of-the-art technologies, such as genomic and structural biology tools, and high-throughput screening platforms have become increasingly common in infectious disease research. Drug repositioning has played a key part in improving the lives of those suffering from these conditions, as evidenced by successful precedents and recent studies on preeminent parasitic disorders.

PMID: 27365271 [PubMed - as supplied by publisher]

Can you teach old drugs new tricks?

Nature. 2016 Jun 16;534(7607):314-6

Authors: Nosengo N

PMID: 27306171 [PubMed - indexed for MEDLINE]

Drug repurposing for chronic myeloid leukemia: in silico and in vitro investigation of DrugBank database for allosteric Bcr-Abl inhibitors.

J Biomol Struct Dyn. 2016 Jun 29;:1-16

Authors: Singh VK, Chang HH, Kuo CC, Shiao HY, Hsieh HP, Coumar MS

Abstract
Chronic myeloid leukemia (CML) is caused by chromosomal rearrangement resulting in the expression of Bcr-Abl fusion protein with deregulated Abl tyrosine kinase activity. Approved drugs - imatinib, dasatinib, nilotinib, and ponatinib - target the ATP-binding site of Abl kinase. Even though these drugs are initially effective, long-term usefulness is limited by the development of resistance. To overcome this problem, targeting the allosteric site of Abl kinase, which is remote from the ATP-binding site is found to be a useful strategy. In this study, structure-based and ligand-based virtual screening methods were applied to narrow down possible drugs (from DrugBank database) that could target the allosteric site of Abl kinase. Detailed investigations of the selected drugs in the allosteric site of Abl kinase, using molecular dynamics and steered molecular dynamics simulation shows that gefitinib, an EGFR inhibitor approved for the treatment of lung cancer, could bind effectively to the allosteric site of Bcr-Abl. More interestingly, gefitinib was found to enhance the ability of imatinib to bind at the ATP-binding site of Bcr-Abl kinase. Based on the in silico findings, gefitinib was tested in combination with imatinib in K562 CML cell line using MTT cell proliferation assay and found to have a synergistic antiproliferative activity. Further detailed mechanistic study could help to unravel the full potential of imatinib - gefitinib combination for the treatment of CML.

PMID: 27353341 [PubMed - as supplied by publisher]

Inflammatory pathway network-based drug repositioning and molecular phenomics.

Mol Biosyst. 2016 Jun 27;

Authors: Gu J, Crosier PS, Hall CJ, Chen L, Xu X

Abstract
Inflammation is a protective biological response to body/tissue damage that involves immune cells, blood vessels and molecular mediators. In this work, we constructed the pathway network of inflammation, including 11 sub-pathways of inflammatory factors. Pathway-based network efficiency and network flux were adopted to evaluate drug efficacy. By using approved and experimentally validated anti-inflammatory drugs as training sets, a predictive model was built to screen potential anti-inflammatory drugs from approved drugs in DrugBank. This drug repositioning approach would bring a fast and cheap way to find new indications for approved drugs. Moreover, molecular phenomics profiles of the expression of inflammatory factors will provide new insight into the drug mechanism of action.

PMID: 27345454 [PubMed - as supplied by publisher]

Bedaquiline, an FDA-approved antibiotic, inhibits mitochondrial function and potently blocks the proliferative expansion of stem-like cancer cells (CSCs).

Aging (Albany NY). 2016 Jun 22;

Authors: Fiorillo M, Lamb R, Tanowitz HB, Cappello AR, Martinez-Outschoorn UE, Sotgia F, Lisanti MP

Abstract
Bedaquiline (a.k.a., Sirturo) is an anti-microbial agent, which is approved by the FDA for the treatment of multi-drug resistant pulmonary tuberculosis (TB). Bedaquiline is a first-in-class diaryl-quinoline compound, that mechanistically inhibits the bacterial ATP-synthase, and shows potent activity against both drug-sensitive and drug-resistant TB. Interestingly, eukaryotic mitochondria originally evolved from engulfed aerobic bacteria. Thus, we hypothesized that, in mammalian cells, bedaquiline might also target the mitochondrial ATP-synthase, leading to mitochondrial dysfunction and ATP depletion. Here, we show that bedaquiline has anti-cancer activity, directed against Cancer Stem-like Cells (CSCs). More specifically, we demonstrate that bedaquiline treatment of MCF7 breast cancer cells inhibits mitochondrial oxygen-consumption, as well as glycolysis, but induces oxidative stress. Importantly, bedaquiline significantly blocks the propagation and expansion of MCF7-derived CSCs, with an IC-50 of approx. 1-μM, as determined using the mammosphere assay. Similarly, bedaquiline also reduces both the CD44+/CD24low/- CSC and ALDH+ CSC populations, under anchorage-independent growth conditions. In striking contrast, bedaquiline significantly increases oxygen consumption in normal human fibroblasts, consistent with the fact that it is well-tolerated in patients treated for TB infections. As such, future pre-clinical studies and human clinical trials in cancer patients may be warranted. Interestingly, we also highlight that bedaquiline shares certain structural similarities with trans-piceatannol and trans-resveratrol, which are known natural flavonoid inhibitors of the mitochondrial ATP-synthase (complex V) and show anti-aging properties.

PMID: 27344270 [PubMed - as supplied by publisher]

Pathway and network-based strategies to translate genetic discoveries into effective therapies.

Hum Mol Genet. 2016 Jun 23;

Authors: Greene CS, Voight BF

Abstract
One way to design a drug is to attempt to phenocopy a genetic variant that is known to have the desired effect. In general, drugs that are supported by genetic associations progress further in the development pipeline. However, the number of associations that are candidates for development into drugs is limited because many associations are in noncoding regions or difficult to target genes. Approaches that overlay information from pathway databases or biological networks can expand the potential target list. In cases where the initial variant is not targetable or there is no variant with the desired effect, this may reveal new means to target a disease. In this review we discuss recent examples in the domain of pathway and networkbased drug repositioning from genetic associations. We highlight important caveats and challenges for the field, and we discuss opportunities for further development.

PMID: 27340225 [PubMed - as supplied by publisher]

The anthelmintic niclosamide inhibits colorectal cancer cell lines via modulation of the canonical and noncanonical Wnt signaling pathway.

J Surg Res. 2016 Jun 1;203(1):193-205

Authors: Monin MB, Krause P, Stelling R, Bocuk D, Niebert S, Klemm F, Pukrop T, Koenig S

Abstract
BACKGROUND: Wnt/β-catenin signaling is known to play an important role in colorectal cancer (CRC). Niclosamide, a salicylamide derivative used in the treatment of tapeworm infections, targets the Wnt/β-catenin pathway. The objective of this study was to investigate niclosamide as a therapeutic agent against CRC.
METHODS: The antiproliferative effects of 1, 3, 10, and 50 μM concentrations of niclosamide on human (SW480 and SW620) and rodent (CC531) CRC cell lines were determined by MTS assay and direct cell count. The lymphoid enhancer-binding factor 1/transcription factor (LEF/TCF) reporter assay monitored the activity of Wnt signaling. Immunofluorescence staining demonstrated the expression pattern of active β-catenin. Gene expression of canonical and noncanonical Wnt signaling components was analyzed using qRT-PCR. Western blot analysis was performed with antibodies detecting nuclear localization of β-catenin and c-jun.
RESULTS: Cell proliferation in CRC cell lines was blocked dose dependently after 12 and 24 h of incubation. The Wnt promoter activity of LEF/TCF significantly decreased with niclosamide concentrations of 10 and 50 μM after 12 h of incubation. Active β-catenin did not shift from the nuclear to the cytosolic pool. However, canonical target genes (met, MMP7, and cyclin D1) as well as the coactivating factor Bcl9 were downregulated, whereas the noncanonical key player c-jun was clearly activated.
CONCLUSIONS: Niclosamide treatment is associated with an inhibitory effect on CRC development and reduced Wnt activity. It may exert its effect by interfering with the nuclear β-catenin-Bcl9-LEF/TCF triple-complex and by upregulation of c-jun representing noncanonical Wnt/JNK signaling. Thus, our findings warrant further research into this substance as a treatment option for patients with advanced CRC.

PMID: 27338550 [PubMed - in process]

Molecular Docking for Identification of Potential Targets for Drug Repurposing.

Curr Top Med Chem. 2016 May 30;

Authors: Luo H, Mattes W, Mendrick DL, Hong H

Abstract
Using existing drugs for new indications (drug repurposing) is an effective method not only to reduce drug development time and costs but also to develop treatments for new disease including those that are rare. In order to discover novel indications, potential target identification is a necessary step. One widely used method to identify potential targets is through molecule docking. It requires no prior information except structure inputs from both the drug and the target, and can identify potential targets for a given drug, or identify potential drugs for a specific target. Though molecular docking is popular for drug development and repurposing, challenges remain for the method. In order to improve the prediction accuracy, optimizing the target conformation, considering the solvents and adding co-binders to the system are possible solutions.

PMID: 27334201 [PubMed - as supplied by publisher]

Drug repositioning through network pharmacology.

Curr Top Med Chem. 2016 May 30;

Authors: Ye H, Wei J, Tang K, Feuers R, Hong H

Abstract
Low drug productivity has been a significant problem of the pharmaceutical industry for several decades even though numerous novel technologies were introduced during this period. Currently pharmacologic dogma, "single drug, single target, single disease", is at the root of the lack of drug productivity. From a systems biology viewpoint, network pharmacology has been proposed to complement established and guiding pharmacologic approaches. The rationale for network pharmacology as a major component of drug discovery and development is that a disease can be caused by perturbation of the disease-causing network and a drug may be designed to interact with multiple targets for modulation of such a network from the disease status toward normal status. Therefore, network pharmacology has been applied to guide and assist in drug repositioning. Drugs exerting their therapeutic effects may directly target disease-associated proteins, but they may also modulate the pathways involved in the pathological process. In this review, we discuss the progresses and prospects in network pharmacology, focusing on drug off-targets discovery, disease-associated protein identification, and pathway analysis for elucidating relationships between drug targets and disease-associated proteins.

PMID: 27334200 [PubMed - as supplied by publisher]

Methods to Profile the Macromolecular Targets of Small Compounds.

Curr Top Med Chem. 2016 May 30;

Authors: Zhu J, Wang W, Chen X

Abstract
Small compounds constitute most of the available medicines. However, their stereophysical and stereochemical properties are relatively simple, which typically results in promiscuity in their interactions with human proteins. Such promiscuity has caused problems in our past efforts to discover and develop new drugs, but at the same time, it also brought new opportunities to exploit the off-target interactions between small compounds and human proteins for novel or improved therapeutics, e.g. in the applications of polypharmacology, drug repositioning, and designing drug combinations. In this direction, identifying the full profile of macromolecules that a small compound may interact with is of fundamental importance to harnessing the positive side of small compound promiscuity. This review summarizes available experimental and computational approaches that identify macromolecular targets for small compounds. The principle, application, performance, limitation and availability of these approaches are discussed.

PMID: 27334197 [PubMed - as supplied by publisher]

Human Pluripotent Stem Cell-derived Cortical Neurons for High Throughput Medication Screening in Autism: A Proof of Concept Study in SHANK3 Haploinsufficiency Syndrome.

EBioMedicine. 2016 May 27;

Authors: Darville H, Poulet A, Rodet-Amsellem F, Chatrousse L, Pernelle J, Boissart C, Héron D, Nava C, Perrier A, Jarrige M, Cogé F, Millan MJ, Bourgeron T, Peschanski M, Delorme R, Benchoua A

Abstract
Autism spectrum disorders affect millions of individuals worldwide, but their heterogeneity complicates therapeutic intervention that is essentially symptomatic. A versatile yet relevant model to rationally screen among hundreds of therapeutic options would help improving clinical practice. Here we investigated whether neurons differentiated from pluripotent stem cells can provide such a tool using SHANK3 haploinsufficiency as a proof of principle. A library of compounds was screened for potential to increase SHANK3 mRNA content in neurons differentiated from control human embryonic stem cells. Using induced pluripotent stem cell technology, active compounds were then evaluated for efficacy in correcting dysfunctional networks of neurons differentiated from individuals with deleterious point mutations of SHANK3. Among 202 compounds tested, lithium and valproic acid showed the best efficacy at corrected SHANK3 haploinsufficiency associated phenotypes in cellulo. Lithium pharmacotherapy was subsequently provided to one patient and, after one year, an encouraging decrease in autism severity was observed. This demonstrated that pluripotent stem cell-derived neurons provide a novel cellular paradigm exploitable in the search for specific disease-modifying treatments.

PMID: 27333044 [PubMed - as supplied by publisher]

Repurposing ebselen for treatment of multidrug-resistant staphylococcal infections.

Sci Rep. 2015;5:11596

Authors: Thangamani S, Younis W, Seleem MN

Abstract
Novel antimicrobials and new approaches to developing them are urgently needed. Repurposing already-approved drugs with well-characterized toxicology and pharmacology is a novel way to reduce the time, cost, and risk associated with antibiotic innovation. Ebselen, an organoselenium compound, is known to be clinically safe and has a well-known pharmacology profile. It has shown potent bactericidal activity against multidrug-resistant clinical isolates of staphylococcus aureus, including methicillin- and vancomycin-resistant S. aureus (MRSA and VRSA). We demonstrated that ebselen acts through inhibition of protein synthesis and subsequently inhibited toxin production in MRSA. Additionally, ebselen was remarkably active and significantly reduced established staphylococcal biofilms. The therapeutic efficacy of ebselen was evaluated in a mouse model of staphylococcal skin infections. Ebselen 1% and 2% significantly reduced the bacterial load and the levels of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), and monocyte chemo attractant protein-1 (MCP-1) in MRSA USA300 skin lesions. Furthermore, it acts synergistically with traditional antimicrobials. This study provides evidence that ebselen has great potential for topical treatment of MRSA skin infections and lays the foundation for further analysis and development of ebselen as a potential treatment for multidrug-resistant staphylococcal infections.

PMID: 26111644 [PubMed - indexed for MEDLINE]

Fenofibrate Suppresses Oral Tumorigenesis via Reprogramming Metabolic Processes: Potential Drug Repurposing for Oral Cancer.

Int J Biol Sci. 2016;12(7):786-98

Authors: Jan CI, Tsai MH, Chiu CF, Huang YP, Liu CJ, Chang NW

Abstract
One anticancer strategy suggests targeting mitochondrial metabolism to trigger cell death through slowing down energy production from the Warburg effect. Fenofibrate is a clinical lipid-lowering agent and an effective anticancer drug. In the present study, we demonstrate that fenofibrate provided novel mechanisms for delaying oral tumor development via the reprogramming of metabolic processes. Fenofibrate induced cytotoxicity by decreasing oxygen consumption rate (OCR) that was accompanied with increasing extracellular acidification rate (ECAR) and reducing ATP content. Moreover, fenofibrate caused changes in the protein expressions of hexokinase II (HK II), pyruvate kinase, pyruvate dehydrogenase, and voltage-dependent anion channel (VDAC), which are associated with the Warburg effect. In addition, fenofibrate reprogrammed the metabolic pathway by interrupting the binding of HK II to VDAC. In an oral cancer mouse model, fenofibrate exhibited both preventive and therapeutic efficacy on oral tumorigenesis. Fenofibrate administration suppressed the incidence rate of tongue lesions, reduced the tumor sizes, decreased the tumor multiplicity, and decreased the immunoreactivities of VDAC and mTOR. The molecular mechanisms involved in fenofibrate's ability to delay tumor development included the down-regulation of mTOR activity via TSC1/2-dependent signaling through activation of AMPK and inactivation of Akt, or via a TSC1/2-independent pathway through direct suppression of raptor. Our findings provide a molecular rationale whereby fenofibrate exerts anticancer and additional beneficial effects for the treatment of oral cancer patients.

PMID: 27313493 [PubMed - in process]

Using Social Media Data to Identify Potential Candidates for Drug Repurposing: A Feasibility Study.

JMIR Res Protoc. 2016;5(2):e121

Authors: Rastegar-Mojarad M, Liu H, Nambisan P

Abstract
BACKGROUND: Drug repurposing (defined as discovering new indications for existing drugs) could play a significant role in drug development, especially considering the declining success rates of developing novel drugs. Typically, new indications for existing medications are identified by accident. However, new technologies and a large number of available resources enable the development of systematic approaches to identify and validate drug-repurposing candidates. Patients today report their experiences with medications on social media and reveal side effects as well as beneficial effects of those medications.
OBJECTIVE: Our aim was to assess the feasibility of using patient reviews from social media to identify potential candidates for drug repurposing.
METHODS: We retrieved patient reviews of 180 medications from an online forum, WebMD. Using dictionary-based and machine learning approaches, we identified disease names in the reviews. Several publicly available resources were used to exclude comments containing known indications and adverse drug effects. After manually reviewing some of the remaining comments, we implemented a rule-based system to identify beneficial effects.
RESULTS: The dictionary-based system and machine learning system identified 2178 and 6171 disease names respectively in 64,616 patient comments. We provided a list of 10 common patterns that patients used to report any beneficial effects or uses of medication. After manually reviewing the comments tagged by our rule-based system, we identified five potential drug repurposing candidates.
CONCLUSIONS: To our knowledge, this is the first study to consider using social media data to identify drug-repurposing candidates. We found that even a rule-based system, with a limited number of rules, could identify beneficial effect mentions in patient comments. Our preliminary study shows that social media has the potential to be used in drug repurposing.

PMID: 27311964 [PubMed]

Discovery of New Potential Anti-Infective Compounds Based on Carbonic Anhydrase Inhibitors by Rational Target-Focused Repurposing Approaches.

ChemMedChem. 2016 Jun 15;

Authors: Annunziato G, Angeli A, D'Alba F, Bruno A, Pieroni M, Vullo D, De Luca V, Capasso C, Supuran CT, Costantino G

Abstract
In academia, compound recycling represents an alternative drug discovery strategy to identify new pharmaceutical targets from a library of chemical compounds available in house. Herein we report the application of a rational target-based drug-repurposing approach to find diverse applications for our in-house collection of compounds. The carbonic anhydrase (CA, EC 4.2.1.1) metalloenzyme superfamily was identified as a potential target of our compounds. The combination of a thoroughly validated docking screening protocol, together with in vitro assays against various CA families and isoforms, allowed us to identify two unprecedented chemotypes as CA inhibitors. The identified compounds have the capacity to preferentially bind pathogenic (bacterial/protozoan) CAs over human isoforms and represent excellent hits for further optimization in hit-to-lead campaigns.

PMID: 27304878 [PubMed - as supplied by publisher]

Drug Repurposing Screening Identifies Novel Compounds That Effectively Inhibit Toxoplasma gondii Growth.

mSphere. 2016 Mar-Apr;1(2)

Authors: Dittmar AJ, Drozda AA, Blader IJ

Abstract
The urgent need to develop new antimicrobial therapies has spawned the development of repurposing screens in which well-studied drugs and other types of compounds are tested for potential off-label uses. As a proof-of-principle screen to identify compounds effective against Toxoplasma gondii, we screened a collection of 1,120 compounds for the ability to significantly reduce Toxoplasma replication. A total of 94 compounds blocked parasite replication with 50% inhibitory concentrations of <5 µM. A significant number of these compounds are established inhibitors of dopamine or estrogen signaling. Follow-up experiments with the dopamine receptor inhibitor pimozide revealed that the drug impacted both parasite invasion and replication but did so independently of inhibition of dopamine or other neurotransmitter receptor signaling. Tamoxifen, which is an established inhibitor of the estrogen receptor, also reduced parasite invasion and replication. Even though Toxoplasma can activate the estrogen receptor, tamoxifen inhibits parasite growth independently of this transcription factor. Tamoxifen is also a potent inducer of autophagy, and we find that the drug stimulates recruitment of the autophagy marker light chain 3-green fluorescent protein onto the membrane of the vacuolar compartment in which the parasite resides and replicates. In contrast to other antiparasitic drugs, including pimozide, tamoxifen treatment of infected cells leads to a time-dependent elimination of intracellular parasites. Taken together, these data suggest that tamoxifen restricts Toxoplasma growth by inducing xenophagy or autophagic destruction of this obligate intracellular parasite. IMPORTANCE There is an urgent need to develop new therapies to treat microbial infections, and the repurposing of well-characterized compounds is emerging as one approach to achieving this goal. Using the protozoan parasite Toxoplasma gondii, we screened a library of 1,120 compounds and identified several compounds with significant antiparasitic activities. Among these were pimozide and tamoxifen, which are well-characterized drugs prescribed to treat patients with psychiatric disorders and breast cancer, respectively. The mechanisms by which these compounds target these disorders are known, but we show here that these drugs kill Toxoplasma through novel pathways, highlighting the potential utility of off-target effects in the treatment of infectious diseases.

PMID: 27303726 [PubMed]

Gene-set analysis based on the pharmacological profiles of drugs to identify repurposing opportunities in schizophrenia.

J Psychopharmacol. 2016 Jun 14;

Authors: de Jong S, Vidler LR, Mokrab Y, Collier DA, Breen G

Abstract
Genome-wide association studies (GWAS) have identified thousands of novel genetic associations for complex genetic disorders, leading to the identification of potential pharmacological targets for novel drug development. In schizophrenia, 108 conservatively defined loci that meet genome-wide significance have been identified and hundreds of additional sub-threshold associations harbour information on the genetic aetiology of the disorder. In the present study, we used gene-set analysis based on the known binding targets of chemical compounds to identify the 'drug pathways' most strongly associated with schizophrenia-associated genes, with the aim of identifying potential drug repositioning opportunities and clues for novel treatment paradigms, especially in multi-target drug development. We compiled 9389 gene sets (2496 with unique gene content) and interrogated gene-based p-values from the PGC2-SCZ analysis. Although no single drug exceeded experiment wide significance (corrected p<0.05), highly ranked gene-sets reaching suggestive significance including the dopamine receptor antagonists metoclopramide and trifluoperazine and the tyrosine kinase inhibitor neratinib. This is a proof of principle analysis showing the potential utility of GWAS data of schizophrenia for the direct identification of candidate drugs and molecules that show polypharmacy.

PMID: 27302942 [PubMed - as supplied by publisher]

The Glucose Transporter PfHT1 Is an Antimalarial Target of the HIV Protease Inhibitor Lopinavir.

Antimicrob Agents Chemother. 2015 Oct;59(10):6203-9

Authors: Kraft TE, Armstrong C, Heitmeier MR, Odom AR, Hruz PW

Abstract
Malaria and HIV infection are coendemic in a large portion of the world and remain a major cause of morbidity and mortality. Growing resistance of Plasmodium species to existing therapies has increased the need for new therapeutic approaches. The Plasmodium glucose transporter PfHT is known to be essential for parasite growth and survival. We have previously shown that HIV protease inhibitors (PIs) act as antagonists of mammalian glucose transporters. While the PI lopinavir is known to have antimalarial activity, the mechanism of action is unknown. We report here that lopinavir blocks glucose uptake into isolated malaria parasites at therapeutically relevant drug levels. Malaria parasites depend on a constant supply of glucose as their primary source of energy, and decreasing the available concentration of glucose leads to parasite death. We identified the malarial glucose transporter PfHT as a target for inhibition by lopinavir that leads to parasite death. This discovery provides a mechanistic basis for the antimalarial effect of lopinavir and provides a direct target for novel drug design with utility beyond the HIV-infected population.

PMID: 26248369 [PubMed - indexed for MEDLINE]

Cancer Drug Development Using Drosophila as an in vivo Tool: From Bedside to Bench and Back.

Trends Pharmacol Sci. 2016 Jun 10;

Authors: Yadav AK, Srikrishna S, Gupta SC

Abstract
The fruit fly Drosophila melanogaster has been used for modeling cancer and as an in vivo tool for the validation and/or development of cancer therapeutics. The impetus for the use of Drosophila in cancer research stems from the high conservation of its signaling pathways, lower genetic redundancy, short life cycle, genetic amenability, and ease of maintenance. Several cell signaling pathways in Drosophila have been used for cancer drug development. The efficacy of combination therapy and uptake/bioavailability of drugs have also been studied. Drosophila has been validated using several FDA-approved drugs, suggesting a potential application of this model in drug repurposing. The model is emerging as a powerful tool for high-throughput screening and should significantly reduce the cost and time associated with drug development. In this review we discuss the applications of Drosophila in cancer drug development. The advantages and limitations of the model are discussed.

PMID: 27298020 [PubMed - as supplied by publisher]