Drug Repositioning

"drug repositioning" OR "drug repurposing"; +6 new citations

Tue, 2019-09-03 08:17

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"drug repositioning" OR "drug repurposing"

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Categories: Literature Watch

Salsalate, but not metformin or canagliflozin, slows kidney cyst growth in an adult-onset mouse model of polycystic kidney disease.

Mon, 2019-09-02 07:52
Related Articles

Salsalate, but not metformin or canagliflozin, slows kidney cyst growth in an adult-onset mouse model of polycystic kidney disease.

EBioMedicine. 2019 Aug 28;:

Authors: Leonhard WN, Song X, Kanhai AA, Iliuta IA, Bozovic A, Steinberg GR, Peters DJM, Pei Y

Abstract
BACKGROUND: Multiple preclinical studies have highlighted AMP-activated protein kinase (AMPK) as a potential therapeutic target for autosomal dominant polycystic kidney disease (ADPKD). Both metformin and canagliflozin indirectly activate AMPK by inhibiting mitochondrial function, while salsalate is a direct AMPK activator. Metformin, canagliflozin and salsalate (a prodrug dimer of salicylate) are approved for clinical use with excellent safety profile. Although metformin treatment had been shown to attenuate experimental cystic kidney disease, there are concerns that therapeutic AMPK activation in human kidney might require a higher oral metformin dose than can be achieved clinically.
METHODS: In this study, we tested metformin-based combination therapies for their additive (metformin plus canagliflozin) and synergistic (metformin plus salsalate) effects and each drug individually in an adult-onset conditional Pkd1 knock-out mouse model (n = 20 male/group) using dosages expected to yield clinically relevant drug levels.
FINDINGS: Compared to untreated mutant mice, treatment with salsalate or metformin plus salsalate improved kidney survival (i.e. blood urea nitrogen <20 mmol/L at the time of sacrifice) and reduced cystic kidney disease severity. However, the effects of metformin plus salsalate did not differ from salsalate alone; and neither metformin nor canagliflozin was effective. Protein expression and phosphorylation analyses indicated that salsalate treatment was associated with reduction in mTOR (mammalian target of rapamycin) activity and cellular proliferation in Pkd1 mutant mouse kidneys. Global gene expression analyses suggested that these effects were linked to restoration of mitochondrial function and suppression of inflammation and fibrosis.
INTERPRETATION: Salsalate is a highly promising candidate for drug repurposing and clinical testing in ADPKD.

PMID: 31473186 [PubMed - as supplied by publisher]

Categories: Literature Watch

Perceptions of using lithium in fracture management: a survey of orthopaedic surgeons, fracture patients and the general public.

Sun, 2019-09-01 07:27
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Perceptions of using lithium in fracture management: a survey of orthopaedic surgeons, fracture patients and the general public.

BMC Musculoskelet Disord. 2019 Aug 31;20(1):389

Authors: Vachhani K, Whyne CM, Schaffer A, Nam D

Abstract
BACKGROUND: Lithium, an established psychiatric medication, has recently been shown to enhance new bone formation in preclinical fracture models. Current research is focused on evaluating the efficacy of low-dose, short-term lithium treatment to improve long bone fracture healing through a Phase II randomized clinical trial (LiFT NCT02999022). In working towards future applications of lithium for fracture management, this study aimed to understand the current perceptions of lithium as a psychiatric drug and the potential barriers to its orthopaedic adoption.
METHODS: Three questionnaires, evaluating knowledge about lithium and willingness to embrace its use in fracture healing were disseminated among the general population, fracture patients eligible for the LiFT (Lithium for Fracture Treatment) trial and orthopaedic surgeons across Canada.
RESULTS: Of the 768 public respondents, 84% were willing to take a medication that would aid fracture healing but only 62.6% if the medication was lithium. Willingness dropped to 44.6% among the 168 respondents who knew about the psychiatric use of lithium. Lack of sufficient knowledge (n = 50) and concerns about side effects including effects on the brain (n = 74) were the main reasons cited by those who were unwilling to use lithium. Of the 29 fracture patients, only 20 patients had previously heard of lithium. Of these, 40% were willing to take lithium for fracture healing with an additional 10% if the dose was low or if the intake duration was short. Only 50% knew that lithium has side effects. Of the 43 orthopaedic surgeons, 38 surgeons knew about clinical use of lithium. Of these, 68% knew that lithium has side effects and 29% knew that it interacts with other drugs. While most agreed that new strategies are needed to improve fracture management, only 68% were willing to prescribe lithium for fractures with an additional 16% if there is scientific evidence and/or a standard dosing protocol.
CONCLUSIONS: This study identified a lack of knowledge about uses and side effects of lithium among all three cohorts. A robust educational framework for orthopaedic surgeons, their patients and the members of their clinical care teams will be essential to widespread repurposing of lithium for fracture care.

PMID: 31470828 [PubMed - in process]

Categories: Literature Watch

PDE3 Inhibitors Repurposed as Treatments for Age-Related Cognitive Impairment.

Fri, 2019-08-30 06:33
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PDE3 Inhibitors Repurposed as Treatments for Age-Related Cognitive Impairment.

Mol Neurobiol. 2019 Jun;56(6):4306-4316

Authors: Yanai S, Endo S

Abstract
As the population of older individuals grows worldwide, researchers have increasingly focused their attention on identifying key molecular targets of age-related cognitive impairments, with the aim of developing possible therapeutic interventions. Two such molecules are the intracellular cyclic nucleotides, cAMP and cGMP. These second messengers mediate fundamental aspects of brain function relevant to memory, learning, and cognitive function. Consequently, phosphodiesterases (PDEs), which hydrolyze cAMP and cGMP, are promising targets for the development of cognition-enhancing drugs. Inhibitors that target PDEs work by elevating intracellular cAMP. In this review, we provide an overview of different PDE inhibitors, and then we focus on pharmacological and physiological effects of PDE3 inhibitors in the CNS and peripheral tissues. Finally, we discuss findings from experimental and preliminary clinical studies and the potential beneficial effects of the PDE3 inhibitor cilostazol on age-related cognitive impairments. In the innovation pipeline of pharmaceutical development, the antiplatelet agent cilostazol has come into the spotlight as a novel treatment for mild cognitive impairment. Overall, the repurposing of cilostazol may represent a potentially promising way to treat mild cognitive impairment, Alzheimer's disease, and vascular dementia. In this review, we present a brief summary of cAMP signaling and different PDE inhibitors, followed by a discussion of the pharmacological and physiological role of PDE3 inhibitors. In this context, we discuss the repurposing of a PDE3 inhibitor, cilostazol, as a potential treatment for age-related cognitive impairment based on recent research.

PMID: 30311144 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

Repurposing of Tranilast for Potential Neuropathic Pain Treatment by Inhibition of Sepiapterin Reductase in the BH4 Pathway.

Thu, 2019-08-29 09:12
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Repurposing of Tranilast for Potential Neuropathic Pain Treatment by Inhibition of Sepiapterin Reductase in the BH4 Pathway.

ACS Omega. 2019 Jul 31;4(7):11960-11972

Authors: Moore BJR, Islam B, Ward S, Jackson O, Armitage R, Blackburn J, Haider S, McHugh PC

Abstract
Tetrahydrobiopterin (BH4) is a cofactor in the production of various signaling molecules including nitric oxide, dopamine, adrenaline, and noradrenaline. BH4 levels are critical for processes associated with cardiovascular function, inflammation, mood, pain, and neurotransmission. Increasing pieces of evidence suggest that BH4 is upregulated in chronic pain. Sepiapterin reductase (SPR) catalyzes both the reversible reduction of sepiapterin to dihydrobiopterin (BH2) and 6-pyruvoyl-tetrahydrobiopterin to BH4 within the BH4 pathway. Therefore, inhibition of SPR by small molecules can be used to control BH4 production and ultimately alleviate chronic pain. Here, we have used various in silico and in vitro experiments to show that tranilast, licensed for use in bronchial asthma, can inhibit sepiapterin reduction by SPR. Docking and molecular dynamics simulations suggest that tranilast can bind to human SPR (hSPR) at the same site as sepiapterin including S157, one of the catalytic triad residues of hSPR. Colorimetric assays revealed that tranilast was nearly twice as potent as the known hSPR inhibitor, N-acetyl serotonin. Tranilast was able to inhibit hSPR activity both intracellularly and extracellularly in live cells. Triple quad mass spectrophotometry of cell lysates showed a proportional decrease of BH4 in cells treated with tranilast. Our results suggest that tranilast can act as a potent hSPR inhibitor and therefore is a valid candidate for drug repurposing in the treatment of chronic pain.

PMID: 31460307 [PubMed]

Categories: Literature Watch

Large-Scale Target Identification of Herbal Medicine Using a Reverse Docking Approach.

Thu, 2019-08-29 09:12
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Large-Scale Target Identification of Herbal Medicine Using a Reverse Docking Approach.

ACS Omega. 2019 Jun 30;4(6):9710-9719

Authors: Zhang H, Pan J, Wu X, Zuo AR, Wei Y, Ji ZL

Abstract
Herbal medicine has been used to countermine various diseases for centuries. However, most of the therapeutic targets underlying herbal therapy remain unclear, which largely slow down the novel drug discovery process from natural products. In this study, we developed a novel computational pipeline for assisting de novo identification of protein targets for herbal ingredients. The pipeline involves pharmacophore comparison and reverse ligand-protein docking simulation in a high throughput manner. We evaluated the pipeline using three traditional Chinese medicine ingredients such as acteoside, quercetin, and epigallocatechin gallate as examples. A majority of current known targets of these ingredients were successfully identified by the pipeline. Structural comparative analyses confirmed that the predicted ligand-target interactions used the same binding pockets and binding modes as those of known ligand-target interactions. Furthermore, we illustrated the mechanism of actions of the ingredients by constructing the pharmacological networks on the basis of the predicted target profiles. In summary, we proposed an efficient and economic option for large-scale target exploration in the herb study. This pipeline will be particularly valuable in aiding precise drug discovery and drug repurposing from natural products.

PMID: 31460061 [PubMed]

Categories: Literature Watch

Repurposing of sodium valproate in colon cancer associated with diabetes mellitus: Role of HDAC inhibition.

Thu, 2019-08-29 06:12
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Repurposing of sodium valproate in colon cancer associated with diabetes mellitus: Role of HDAC inhibition.

Eur J Pharm Sci. 2018 08 30;121:188-199

Authors: Patel MM, Patel BM

Abstract
BACKGROUND AND PURPOSE: Diabetic patients are at greater risk for colon cancer. Histone deacetylases (HDACs) serve as common target for both. The key objective of the study was to evaluate the effect of sodium valproate in type 2 diabetes mellitus associated colon cancer.
EXPERIMENTAL APPROACH: High fat diet and streptozotocin were used to induce type 2 diabetes. Following this, after diabetes confirmation, colon cancer was induced using 1,2 dimethylhydrazine (25 mg/kg, s.c.) once weekly from 7th week to 20th weeks. Sodium valproate (200 mg/kg) treatment was given from 20th to 24th week. At the end of 24 weeks, several enzymatic and biochemical parameters, were estimated. MTT, clonogenic and scratch wound healing assay were carried out in HCT-15 cell line.
KEY RESULTS: Hyperglycemia, hyperinsulinemia, increase in cytokines (TNF-α and IL-1β) and carcinoembryonic antigen and presence of proliferating cells was seen in disease control animals which was prevented by sodium valproate treatment. Overexpression of relative HDAC2 mRNA levels was found in diseased control animals, which was reduced by sodium valproate treatment. IC50 of sodium valproate was found to be 3.40 mM and 3.73 mM at 48 h and 72 h respectively on HCT-15 cell line. Sodium valproate also dose dependently prevented colony formation and cell migration.
CONCLUSION AND IMPLICATIONS: Sodium valproate can be considered for repurposing in colon cancer associated with diabetes mellitus.

PMID: 29852291 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

Improving therapy of severe infections through drug repurposing of synergistic combinations.

Wed, 2019-08-28 14:47
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Improving therapy of severe infections through drug repurposing of synergistic combinations.

Curr Opin Pharmacol. 2019 Aug 24;48:92-98

Authors: Cheng YS, Williamson PR, Zheng W

Abstract
Infections from multidrug resistant (MDR) pathogens and emerging viruses present challenges for effective clinical treatments. Drug repurposing and combination screens may provide therapies at a fraction of the time and cost of traditional methods of drug development. Synergistic combinations of two or three known compounds can increase therapeutic efficacy and reduce concentrations required for individual drugs, in turn, reducing the risk of drug toxicity. Using libraries of approved drugs, traditionally non-antibiotic compounds identified in repurposing screens can quickly move into clinical trials, since safety profiles have been previously established. Herein we summarize recent advances in identifying synergistic drug combinations and the use of drug screens for personalized medicine treatments of infections caused by MDR pathogens and emerging viruses.

PMID: 31454708 [PubMed - as supplied by publisher]

Categories: Literature Watch

Calf Clinical Model of Cryptosporidiosis for Efficacy Evaluation of Therapeutics.

Wed, 2019-08-28 14:47
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Calf Clinical Model of Cryptosporidiosis for Efficacy Evaluation of Therapeutics.

Methods Mol Biol. 2020;2052:253-282

Authors: Riggs MW, Schaefer DA

Abstract
Cryptosporidiosis, caused by the apicomplexan parasite Cryptosporidium parvum, is a moderate-to-severe diarrheal disease now recognized as one of the leading causes of morbidity and mortality in livestock globally, and in humans living in resource-limited parts of the world, particularly those with AIDS or malnourished individuals. This recognition has fueled efforts for the discovery of effective therapeutics. While recent progress in drug discovery has been encouraging, there are presently no acceptably effective parasite-specific drugs for the disease. The urgent need for new drug discovery or drug repurposing has also increased the need for refined animal models of clinical disease for therapeutic efficacy evaluation. Here, we describe an acute model of cryptosporidiosis using newborn calves to evaluate well-defined clinical and parasitological parameter outcomes, including the effect on diarrhea severity and duration, oocyst numbers produced, and multiple measures of clinical health. The model is highly reproducible and provides unequivocal direct measures of treatment efficacy on diarrhea severity and parasite replication.

PMID: 31452167 [PubMed - in process]

Categories: Literature Watch

Drug repurposing studies of PARP inhibitors as a new therapy for inherited retinal degeneration.

Wed, 2019-08-28 14:47
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Drug repurposing studies of PARP inhibitors as a new therapy for inherited retinal degeneration.

Cell Mol Life Sci. 2019 Aug 26;:

Authors: Sahaboglu A, Miranda M, Canjuga D, Avci-Adali M, Savytska N, Secer E, Feria-Pliego JA, Kayık G, Durdagi S

Abstract
The enzyme poly-ADP-ribose-polymerase (PARP) has important roles for many forms of DNA repair and it also participates in transcription, chromatin remodeling and cell death signaling. Currently, some PARP inhibitors are approved for cancer therapy, by means of canceling DNA repair processes and cell division. Drug repurposing is a new and attractive aspect of therapy development that could offer low-cost and accelerated establishment of new treatment options. Excessive PARP activity is also involved in neurodegenerative diseases including the currently untreatable and blinding retinitis pigmentosa group of inherited retinal photoreceptor degenerations. Hence, repurposing of known PARP inhibitors for patients with non-oncological diseases might provide a facilitated route for a novel retinitis pigmentosa therapy. Here, we demonstrate and compare the efficacy of two different PARP inhibitors, BMN-673 and 3-aminobenzamide, by using a well-established retinitis pigmentosa model, the rd1 mouse. Moreover, the mechanistic aspects of the PARP inhibitor-induced protection were also investigated in the present study. Our results showed that rd1 rod photoreceptor cell death was decreased by about 25-40% together with the application of these two PARP inhibitors. The wealth of human clinical data available for BMN-673 highlights a strong potential for a rapid clinical translation into novel retinitis pigmentosa treatments. Remarkably, we have found that the efficacy of 3 aminobenzamide was able to decrease PARylation at the nanomolar level. Our data also provide a link between PARP activity with the Wnt/β-catenin pathway and the major intracellular antioxidant concentrations behind the PARP-dependent retinal degeneration. In addition, molecular modeling studies were integrated with experimental studies for better understanding of the role of PARP1 inhibitors in retinal degeneration.

PMID: 31451894 [PubMed - as supplied by publisher]

Categories: Literature Watch

In silico Guided Drug Repurposing: Discovery of New Competitive and Non-competitive Inhibitors of Falcipain-2.

Tue, 2019-08-27 08:17
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In silico Guided Drug Repurposing: Discovery of New Competitive and Non-competitive Inhibitors of Falcipain-2.

Front Chem. 2019;7:534

Authors: Alberca LN, Chuguransky SR, Álvarez CL, Talevi A, Salas-Sarduy E

Abstract
Malaria is among the leading causes of death worldwide. The emergence of Plasmodium falciparum resistant strains with reduced sensitivity to the first line combination therapy and suboptimal responses to insecticides used for Anopheles vector management have led to renewed interest in novel therapeutic options. Here, we report the development and validation of an ensemble of ligand-based computational models capable of identifying falcipain-2 inhibitors, and their subsequent application in the virtual screening of DrugBank and Sweetlead libraries. Among four hits submitted to enzymatic assays, two (odanacatib, an abandoned investigational treatment for osteoporosis and bone metastasis, and the antibiotic methacycline) confirmed inhibitory effects on falcipain-2, with Ki of 98.2 nM and 84.4 μM. Interestingly, Methacycline proved to be a non-competitive inhibitor (α = 1.42) of falcipain-2. The effects of both hits on falcipain-2 hemoglobinase activity and on the development of P. falciparum were also studied.

PMID: 31448257 [PubMed]

Categories: Literature Watch

A rational search for discovering potential neutraligands of human complement fragment 5a (hC5a).

Tue, 2019-08-27 08:17
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A rational search for discovering potential neutraligands of human complement fragment 5a (hC5a).

Bioorg Med Chem. 2019 Aug 19;:115052

Authors: Mishra R, Rana S

Abstract
The human complement fragment 5a (hC5a) is an extremely potent proinflammatory glycoprotein, which upon binding to C5aR triggers a plethora of immune and non-immunological responses in humans. Dysregulation of complement system is associated with the upregulation of hC5a, leading to the surge of proinflammatory cytokines, which further exacerbate the chronic inflammation induced pathological conditions. Thus, hC5a is considered as a major pharmacological target for developing complement therapeutics that can directly or indirectly modulate the function of hC5a. However, the idea of small molecules, directly neutralizing the function of excessive hC5a remains unexplored in the literature. By recruiting cheminformatics approach, the avenue of drug repositioning is explored in the current study for discovering novel neutraligands of hC5a. The systematic exercise yields a pool of potential neutraligands, from which four FDA approved drugs, such as carprofen, oxaprozin, sulindac and raloxifene have been subjected to a battery of computational and biophysical studies against hC5a. The data obtained from docking, molecular dynamics, and molecular mechanics Poisson-Boltzmann surface area studies, strongly correlate with the data obtained from the circular dichroism, steady state fluorescence, and fluorescence quenching studies, involving the recombinant hC5a and the selected drugs. The proof of the concept study successfully documents the rational discovery of first generation template neutraligands of hC5a through drug repositioning approach and suggests that the selected drugs perhaps bind functionally distinct hot spots on hC5a. The identified neutraligands can be subsequently optimized as complement specific therapeutics for strongly modulating the hC5a-C5aR signaling axes.

PMID: 31447248 [PubMed - as supplied by publisher]

Categories: Literature Watch

Integrative transcriptome imputation reveals tissue-specific and shared biological mechanisms mediating susceptibility to complex traits.

Sun, 2019-08-25 07:31
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Integrative transcriptome imputation reveals tissue-specific and shared biological mechanisms mediating susceptibility to complex traits.

Nat Commun. 2019 Aug 23;10(1):3834

Authors: Zhang W, Voloudakis G, Rajagopal VM, Readhead B, Dudley JT, Schadt EE, Björkegren JLM, Kim Y, Fullard JF, Hoffman GE, Roussos P

Abstract
Transcriptome-wide association studies integrate gene expression data with common risk variation to identify gene-trait associations. By incorporating epigenome data to estimate the functional importance of genetic variation on gene expression, we generate a small but significant improvement in the accuracy of transcriptome prediction and increase the power to detect significant expression-trait associations. Joint analysis of 14 large-scale transcriptome datasets and 58 traits identify 13,724 significant expression-trait associations that converge on biological processes and relevant phenotypes in human and mouse phenotype databases. We perform drug repurposing analysis and identify compounds that mimic, or reverse, trait-specific changes. We identify genes that exhibit agonistic pleiotropy for genetically correlated traits that converge on shared biological pathways and elucidate distinct processes in disease etiopathogenesis. Overall, this comprehensive analysis provides insight into the specificity and convergence of gene expression on susceptibility to complex traits.

PMID: 31444360 [PubMed - in process]

Categories: Literature Watch

Targeting the nsp2 Cysteine Protease of Chikungunya Virus Using FDA Approved Library and Selected Cysteine Protease Inhibitors.

Sun, 2019-08-25 07:31
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Targeting the nsp2 Cysteine Protease of Chikungunya Virus Using FDA Approved Library and Selected Cysteine Protease Inhibitors.

Pathogens. 2019 Aug 15;8(3):

Authors: Kumar P, Kumar D, Giri R

Abstract
Chikungunya virus (CHIKV) infection is one of the major public health concerns, leading thousands of cases every year in rural as well as urban regions of several countries worldwide, few to mention are India, Philippines, Indonesia, and also in American countries. The structural and non-structural proteins of CHIKV are structurally and functionally similar to other alphaviruses such as Sindbis virus, Venezuelan Equine Encephalitis virus. The precursor protein of non-structural proteins is cleaved by proteolytic activity of non-structural protein (nsp2). This multifunctional nsp2 carry out nucleoside-triphosphatase (NTPase) and RNA helicase activity at its N-terminal and protease activity at C-terminal that makes it primarily a drug target to inhibit CHIKV replication. Until the current date, no suitable treatment for chikungunya infection is available. The introduction of a new drug into the market is a lengthy process, therefore, drug repurposing is now familiar approach that cut off the time and cost of drug discovery. In this study, we have implemented this approach with Food and Drug Administration (FDA) approved drugs and known cysteine protease inhibitors against CHIKV nsp2 protease using structure-based drug discovery. Our extensive docking and molecular dynamics simulations studies leads to two best interacting compounds, Ribostamycin sulfate and E-64, with utmost stable complexes at active site of nsp2 protease. Therefore, these compounds could be suitable for inhibiting CHIKV protease activity, and ultimately the viral replication.

PMID: 31443266 [PubMed]

Categories: Literature Watch

Targeted Treatment Options of Recurrent Radioactive Iodine Refractory Hürthle Cell Cancer.

Sun, 2019-08-25 07:31
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Targeted Treatment Options of Recurrent Radioactive Iodine Refractory Hürthle Cell Cancer.

Cancers (Basel). 2019 Aug 15;11(8):

Authors: Aydemirli MD, Corver W, Beuk R, Roepman P, Solleveld-Westerink N, van Wezel T, Kapiteijn E, Morreau H

Abstract
Objective: To evaluate the efficacy and treatment rationale of Hürthle cell carcinoma (HCC) following a patient with progressive and metastatic HCC. HCC was recently shown to harbor a distinct genetic make-up and the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kiase (PI3K)/AKT signaling pathways are potential targets for anti-cancer agents in the management of recurrent HCC. The presence or absence of gene variants can give a rationale for targeted therapies that could be made available in the context of drug repurposing trials. Methods: Treatment included everolimus, sorafenib, nintedanib, lenvatinib, and panitumumab. Whole genome sequencing (WGS) of metastatic tumor material obtained before administration of the last drug, was performed. We subsequently evaluated the rationale and efficacy of panitumumab in thyroid cancer and control cell lines after epidermal growth factor (EGF) stimulation and treatment with panitumumab using immunofluorescent Western blot analysis. EGF receptor (EGFR) quantification was performed using flow cytometry. Results: WGS revealed a near-homozygous genome (NHG) and a somatic homozygous TSC1 variant, that was absent in the primary tumor. In the absence of RAS variants, panitumumab showed no real-life efficacy. This might be explained by high constitutive AKT signaling in the two thyroid cancer cell lines with NHG, with panitumumab only being a potent inhibitor of pEGFR in all cancer cell lines tested. Conclusions: In progressive HCC, several treatment options outside or inside clinical trials are available. WGS of metastatic tumors might direct the timing of therapy. Unlike other cancers, the absence of RAS variants seems to provide insufficient justification of single-agent panitumumab administration in HCC cases harboring a near-homozygous genome.

PMID: 31443247 [PubMed]

Categories: Literature Watch

Influence of batch effect correction methods on drug induced differential gene expression profiles.

Sat, 2019-08-24 06:57
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Influence of batch effect correction methods on drug induced differential gene expression profiles.

BMC Bioinformatics. 2019 Aug 22;20(1):437

Authors: Zhou W, Koudijs KKM, Böhringer S

Abstract
BACKGROUND: Batch effects were not accounted for in most of the studies of computational drug repositioning based on gene expression signatures. It is unknown how batch effect removal methods impact the results of signature-based drug repositioning. Herein, we conducted differential analyses on the Connectivity Map (CMAP) database using several batch effect correction methods to evaluate the influence of batch effect correction methods on computational drug repositioning using microarray data and compare several batch effect correction methods.
RESULTS: Differences in average signature size were observed with different methods applied. The gene signatures identified by the Latent Effect Adjustment after Primary Projection (LEAPP) method and the methods fitted with Linear Models for Microarray Data (limma) software demonstrated little agreement. The external validity of the gene signatures was evaluated by connectivity mapping between the CMAP database and the Library of Integrated Network-based Cellular Signatures (LINCS) database. The results of connectivity mapping indicate that the genes identified were not reliable for drugs with total sample size (drug + control samples) smaller than 40, irrespective of the batch effect correction method applied. With total sample size larger than 40, the methods correcting for batch effects produced significantly better results than the method with no batch effect correction. In a simulation study, the power was generally low for simulated data with sample size smaller than 40. We observed best performance when using the limma method correcting for two principal components.
CONCLUSION: Batch effect correction methods strongly impact differential gene expression analysis when the sample size is large enough to contain sufficient information and thus the downstream drug repositioning. We recommend including two or three principal components as covariates in fitting models with limma when sample size is sufficient (larger than 40 drug and controls combined).

PMID: 31438848 [PubMed - in process]

Categories: Literature Watch

Targeting cancer stem cells with dietary phytochemical - Repositioned drug combinations.

Sat, 2019-08-24 06:57
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Targeting cancer stem cells with dietary phytochemical - Repositioned drug combinations.

Cancer Lett. 2018 10 01;433:53-64

Authors: Chan MM, Chen R, Fong D

Abstract
The tumor microenvironment is complex with the cancer stem cell (CSC) as a member within its community. This population possesses the capacity to self-renew and to cause cellular heterogeneity of the tumor. CSCs are resistant to conventional anti-proliferative drugs. In order to be curative, it is imperative that CSCs must be eliminated by cancer therapy. A variety of dietary phytochemicals and repositioned drugs can act synergistically with conventional anti-cancer agents. In this review, we advocate the development of a novel approach, namely combination therapy by incorporating both phytochemicals and repositioned drugs to target CSCs. We cover select dietary phytochemicals (curcumin, resveratrol, EGCG, genistein) and repurposed drugs (metformin, niclosamide, thioridazine, chloroquine). Five of the eight (curcumin, resveratrol, EGCG, genistein, metformin) are listed in "The Halifax Project", that explores "the concept of a low-toxicity 'broad-spectrum' therapeutic approach that could simultaneously target many key pathways and mechanisms" [1]. For these compounds, we discuss their mechanisms of action, in which models their anti-CSC activities were identified, as well as advantages, challenges and potentials of combination therapy.

PMID: 29960048 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

Normalization of EEG in depression after antidepressant treatment with sertraline? A preliminary report.

Fri, 2019-08-23 06:27

Normalization of EEG in depression after antidepressant treatment with sertraline? A preliminary report.

J Affect Disord. 2019 Aug 13;259:67-72

Authors: van der Vinne N, Vollebregt MA, Boutros NN, Fallahpour K, van Putten MJAM, Arns M

Abstract
BACKGROUND: MDD patients with abnormal EEG patterns seem more likely to be non-responsive to the antidepressants escitalopram and venlafaxine, but not sertraline, than patients without EEG abnormalities. This finding suggests that patients with both MDD and abnormal EEGs may differentially respond to antidepressant treatment. In the current study, we investigated whether depressed patients with an abnormal EEG show a normalization of the EEG related to antidepressant treatment and response and whether such effect is drug specific, and whether having had early life stress (ELS) increases the chance of abnormal activity.
METHODS: Baseline and week 8 EEGs and depression symptoms were extracted from a large multicenter study (iSPOT-D, n = 1008) where depressed patients were randomized to escitalopram, sertraline, or venlafaxine-XR treatment. We calculated Odds Ratios of EEG normalization and depression response in patients with an abnormal EEG at baseline, comparing sertraline versus other antidepressants.
RESULTS: Fifty seven patients with abnormal EEGs were included. EEGs did not normalize significantly more with sertraline compared to other antidepressants (OR = 1.9, p = .280). However, patients with a normalized EEG taking sertraline were 5.2 times more likely to respond than subjects taking other antidepressants (p = .019). ELS was not significantly related to abnormal activity.
LIMITATIONS: Neurophysiological recordings were limited in time (two times 2-minute EEGs) and statistical power (n = 57 abnormal EEGs).
CONCLUSIONS: Response rates in patients with normalized EEG taking sertraline were significantly larger than in subjects treated with escitalopram/venlafaxine. This adds to personalized medicine and suggests a possible drug repurposing for sertraline.

PMID: 31437703 [PubMed - as supplied by publisher]

Categories: Literature Watch

Discovery of potential Toxoplasma gondii CDPK1 inhibitors with new scaffolds based on the combination of QSAR and scaffold-hopping method with in-vitro validation.

Fri, 2019-08-23 06:27

Discovery of potential Toxoplasma gondii CDPK1 inhibitors with new scaffolds based on the combination of QSAR and scaffold-hopping method with in-vitro validation.

Chem Biol Drug Des. 2019 Aug 22;:

Authors: Zhang P, Jia L, Tian Y, Xi L, Duan R, Chen X, Xiao J, Yao X, Lan J, Li S

Abstract
To discover drugs for toxoplasmosis with less side effects and less probability to get drug resistance is eagerly appealed for pregnant women, infant or immunocompromised patients. In this work, using TgCDPK1 as drug target, we design a method to discover new inhibitors for CDPK1 as potential drug lead for toxoplasmosis with novel scaffolds based on the combination of 2D/3D-QSAR and scaffold-hopping methods. All the binding sites of the potential inhibitors were checked by docking method and only the ones that docked to the most conserved sites of TgCDPK1, which make them have less probability to get drug resistance were remained. As a result, 10 potential inhibitors within 2 new scaffolds were discovered for TgCDPK1 with experimentally verified inhibitory activities in micromole level. The discovery of these inhibitors may contribute to the drug development for toxoplasmosis. Besides, the pipeline which is composed in this work as the combination of QSAR and scaffold-hopping is simple, easy to repeat for researchers without need of in-depth knowledge of pharmacology to get inhibitors with novel scaffolds, which will accelerate the procedure of drug discovery and contribute to the drug repurposing study. This article is protected by copyright. All rights reserved.

PMID: 31436911 [PubMed - as supplied by publisher]

Categories: Literature Watch

EK-DRD: A Comprehensive Database for Drug Repositioning Inspired by Experimental Knowledge.

Thu, 2019-08-22 12:02

EK-DRD: A Comprehensive Database for Drug Repositioning Inspired by Experimental Knowledge.

J Chem Inf Model. 2019 Aug 21;:

Authors: Zhao C, Dai X, Li Y, Guo Q, Zhang J, Zhang X, Wang L

Abstract
Drug repositioning, or the identification of new indications for approved therapeutic drugs, has gained substantial traction with both academics and pharmaceutical companies because it reduces the cost and duration of the drug development pipeline and it reduces the likelihood of unforeseen adverse events. So far, there has not been a systematic effort to identify such opportunities, in part because of the lack of a comprehensive resource for an enormous amount of unsystematic drug repositioning information to support scientists who could benefit from this endeavor. To address this challenge, we developed a new database, Experimental Knowledge-Based Drug Repositioning Database (EK-DRD) by using text and data mining, as well as manual curation. EK-DRD contains experimentally validated drug repositioning annotation for 1861 FDA-approved and 102 withdrawn small molecule drugs. Annotation was done at four levels, using 30,944 target assay records, 3999 cell assay records, 585 organism assay records, and 8910 clinical trial records. Additionally, approximately 1799 repositioning protein or target sequences coupled with 856 related diseases and 1332 pathways are linked to the drug entries. Our web-based software displays a network for integrative relationships between drugs, their repositioning targets, and related diseases. The database is fully searchable and supports extensive text, sequence, chemical structure, and relational query searches. EK-DRD is freely accessible at http://www.idruglab.com/drd/index.php.

PMID: 31433187 [PubMed - as supplied by publisher]

Categories: Literature Watch

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