Repurposing the aldose reductase inhibitor and diabetic neuropathy drug epalrestat for the congenital disorder of glycosylation PMM2-CDG.

Dis Model Mech. 2019 Oct 21;:

Authors: Iyer S, Sam FS, DiPrimio N, Preston G, Verheijen J, Murthy K, Parton Z, Tsang H, Lao J, Morava E, Perlstein EO

Abstract
Phosphomannomutase 2 deficiency, or PMM2-CDG, is the most common congenital disorder of glycosylation affecting over 1,000 patients globally. There are no approved drugs that treat the symptoms or root cause of PMM2-CDG. In order to identify clinically actionable compounds that boost human PMM2 enzyme function, we performed a multi-species drug repurposing screen using a first-ever worm model of PMM2-CDG followed by PMM2 enzyme functional studies in PMM2-CDG patient fibroblasts. Drug repurposing candidates from this study, and drug repurposing candidates from a previously published study using yeast models of PMM2-CDG, were tested for their effect on human PMM2 enzyme activity in PMM2-CDG fibroblasts. Of the 20 repurposing candidates discovered in the worm-based phenotypic screen, 12 are plant-based polyphenols. Insights from structure-activity relationships revealed epalrestat, the only antidiabetic aldose reductase inhibitor approved for use in humans, as a first-in-class PMM2 enzyme activator. Epalrestat increased PMM2 enzymatic activity in four PMM2-CDG patient fibroblast lines with genotypes R141H/F119L, R141H/E139K, R141H/N216I and R141H/F183S. PMM2 enzyme activity gains range from 30% to 400% over baseline depending on genotype. Pharmacological inhibition of aldose reductase by epalrestat may shunt glucose from the polyol pathway to glucose-1,6-bisphosphate, which is an endogenous stabilizer and coactivator of PMM2 homodimerization. Epalrestat is a safe, oral and brain penetrant drug that was approved 27 years ago in Japan to treat diabetic neuropathy in geriatric populations. We demonstrate that epalrestat is the first small molecule activator of PMM2 enzyme activity with the potential to treat peripheral neuropathy and correct the underlying enzyme deficiency in a majority of pediatric and adult PMM2-CDG patients.

PMID: 31636082 [PubMed - as supplied by publisher]

Drug Repurposing Approach for Developing Novel Therapy Against Mupirocin-Resistant Staphylococcus aureus.

Assay Drug Dev Technol. 2019 Oct;17(7):298-309

Authors: Mujwar S, Deshmukh R, Harwansh RK, Gupta JK, Gour A

Abstract
Multidrug resistance (MDR) is a major health issue for the treatment of infectious diseases throughout the world. Staphylococcus aureus (S. aureus) is a Gram-positive bacteria, responsible for various local and systemic infections in humans. The continuous and abrupt use of antibiotics against bacteria such as S. aureus results in the development of resistant strains. Presently, mupirocin (MUP) is the drug of choice against S. aureus and MDR (methicillin-resistant). However, S. aureus has acquired resistance against MUP as well due to isoleucyl-tRNA synthetase (IleS) mutation at sites 588 and 631. Thus, the aim of the present study was to discover novel bioactives against MUP-resistant S. aureus using in silico drug repurposing approaches. In silico drug repurposing techniques were used to obtain suitable bioactive lead molecules such as buclizine, tasosartan, emetine, medrysone, and so on. These lead molecules might be able to resolve this issue. These leads were obtained through molecular docking simulation based virtual screening, which could be promising for the treatment of MUP-resistant S. aureus. The findings of the present work need to be validated further through in vitro and in vivo studies for their clinical application.

PMID: 31634019 [PubMed - in process]

Druggable genome in attention deficit/hyperactivity disorder and its co-morbid conditions. New avenues for treatment.

Mol Psychiatry. 2019 Oct 18;:

Authors: Hegvik TA, Waløen K, Pandey SK, Faraone SV, Haavik J, Zayats T

Abstract
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder with only symptomatic care available. Genome-wide association (GWA) studies can provide a starting point in the search for novel drug targets and possibilities of drug repurposing. Here, we explored the druggable genome in ADHD by utilising GWA studies on ADHD and its co-morbid conditions. First, we explored whether the genes targeted by current ADHD drugs show association with the disorder and/or its co-morbidities. Second, we aimed to identify genes and pathways involved in the biological processes underlying ADHD that can be targeted by pharmacological agents. These ADHD-associated druggable genes and pathways were also examined in co-morbidities of ADHD, as commonalities in their aetiology and management may lead to novel pharmacological insights. Strikingly, none of the genes encoding targets of first-line pharmacotherapeutics for ADHD were significantly associated with the disorder, suggesting that FDA-approved ADHD drugs may act through different mechanisms than those underlying ADHD. In the examined druggable genome, three loci on chromosomes 1, 4 and 12 revealed significant association with ADHD and contained nine druggable genes, five of which encode established drug targets for malignancies, autoimmune and neurodevelopmental disorders. To conclude, we present a framework to assess the druggable genome in a disorder, exemplified by ADHD. We highlight signal transduction and cell adhesion as potential novel avenues for ADHD treatment. Our findings add to knowledge on known ADHD drugs and present the exploration of druggable genome associated with ADHD, which may offer interventions at the aetiological level of the disorder.

PMID: 31628418 [PubMed - as supplied by publisher]

Analysis of defective pathways and drug repositioning in Multiple Sclerosis via machine learning approaches.

Comput Biol Med. 2019 Oct 09;115:103492

Authors: deAndrés-Galiana EJ, Bea G, Fernández-Martínez JL, Saligan LN

Abstract
BACKGROUND: Although some studies show that there could be a genetic predisposition to develop Multiple Sclerosis (MS), attempts to find genetic signatures related to MS diagnosis and development are extremely rare.
METHOD: We carried out a retrospective analysis of two different microarray datasets, using machine learning techniques to understand the defective pathways involved in this disease. We have modeled two data sets that are publicly accessible. The first was used to establish the list of most discriminatory genes; whereas, the second one was utilized for validation purposes.
RESULTS: The analysis provided a list of high discriminatory genes with predictive cross-validation accuracy higher than 95%, both in learning and in blind validation. The results were confirmed via the holdout sampler. The most discriminatory genes were related to the production of Hemoglobin. The biological processes involved were related to T-cell Receptor Signaling and co-stimulation, Interferon-Gamma Signaling and Antigen Processing and Presentation. Drug repositioning via CMAP methodologies highlighted the importance of Trichostatin A and other HDAC inhibitors.
CONCLUSIONS: The defective pathways suggest viral or bacterial infections as plausible mechanisms involved in MS development. The pathway analysis also confirmed coincidences with Epstein-Barr virus, Influenza A, Toxoplasmosis, Tuberculosis and Staphylococcus Aureus infections. Th17 Cell differentiation, and CD28 co-stimulation seemed to be crucial in the development of this disease. Furthermore, the additional knowledge provided by this analysis helps to identify new therapeutic targets.

PMID: 31627017 [PubMed - as supplied by publisher]

Identification of chlorprothixene as a potential drug that induces apoptosis and autophagic cell death in acute myeloid leukemia cells.

FEBS J. 2019 Oct 18;:

Authors: Du Y, Li K, Wang X, Aman KC, Junaid M, Wei D

Abstract
Although acute myeloid leukemia (AML) is a highly heterogeneous malignance, the common molecular mechanisms shared by different AML subtypes play critical roles in AML development. It is possible to identify new drugs that are effective for various AML subtypes based on the common molecular mechanisms. Therefore, we developed a hypothesis-driven bioinformatic drug screening framework by integrating multiple omics data. In this study, we identified that chlorprothixene，a dopamine receptor antagonist, could effectively inhibit growth of AML cells from different subtypes. RNA-seq analysis suggested that chlorprothixene perturbed a series of crucial biological processes such as cell cycle, apoptosis and autophagy in AML cells. Further investigations indicated that chlorprothixene could induce both apoptosis and autophagy in AML cells, and apoptosis and autophagy could act as partners to induce cell death cooperatively. Remarkably, chlorprothixene was found to inhibit tumor growth and induce in situ leukemic cell apoptosis in the murine xenograft model. Furthermore, chlorprothixene treatment could reduce the level of oncofusion proteins PML-RARα and AML1-ETO, thus elevate the expression of apoptosis-related genes and lead to AML cell death. Our results provided new insights for drug repositioning of AML therapy, and confirmed that chlorprothixene might be a potential candidate for treatment of different subtypes of AML by reducing expression of oncofusion proteins.

PMID: 31625692 [PubMed - as supplied by publisher]

Off-label uses of drugs for depression.

Eur J Pharmacol. 2019 Oct 14;:172732

Authors: Skånland SS, Cieslar-Pobuda A

Abstract
The prescription of drugs for depression is rising rapidly. One of the reasons for this trend is their many off-label uses. Up to one third of all prescriptions are for non-indicated use, which in addition to drug repurposing includes different dosing or duration than those recommended. In this review, we elaborate on what antidepressants can treat besides depression. The five classes of drugs for depression are introduced, and their mechanisms of action and serious side effects are described. The most common off-label uses of antidepressants are discussed, with a special focus on treating eating disorders, sleep problems, smoking cessation and managing chronic pain. Depression is often a comorbidity when antidepressants are chosen as therapy, but good therapeutic effects have been observed for other conditions also when depression is not involved. Finally, a new type of antidepressant developed from the hallucinogenic "party drug" ketamine is briefly introduced. This recent development suggest that antidepressants will keep playing a central role in medicine for years to come.

PMID: 31622593 [PubMed - as supplied by publisher]

Selective Estrogen Receptor Modulators (SERMs): Mechanistic Insights Against Microbial Infections.

Curr Mol Med. 2019 Oct 14;:

Authors: Garg A, Singh B, Sharma R, Singh A, Kumar A

Abstract
BACKGROUND: Infections are one of the leading causes of death worldwide and current available treatment remains unsatisfactory due to rise in the cases of antimicrobial resistance. Thus, there is a need for the development of new drugs with different mechanism of action. However, the development of new antimicrobials agents is a long and expensive process. Hence, most of the pharmaceutical companies are looking forward for repurposing already available drugs against microbial infections.
METHODOLOGY: The data related to SERMs and microbial infection has been extracted from Pub Med (from January 1997 to December 2018). A total of 101 studies have been published from 1997 -2018 regarding SERMs and microbial infections.
RESULTS: On the basis of inclusion and exclusion criteria, 25 studies have been included for the analysis of level of evidence regarding antimicrobial effects of SERMs. Emerging reports have indicated the antimicrobial property of selective estrogen receptor modulators (SERMs) against normal and resistant strains under in vitro and in vivo conditions against wide variety of microorganisms through different mechanism of action.
CONCLUSION: In conclusion, SERMs could be developed as a broad spectrum antimicrobial agent alone or in combination with existing antimicrobial agents.

PMID: 31622201 [PubMed - as supplied by publisher]

In Silico Drug Repositioning for Chagas Disease.

Curr Med Chem. 2019 Oct 16;:

Authors: Bellera CL, Alberca LN, Sbaraglini ML, Talevi A

Abstract
Chagas disease is an infectious tropical disease included within the group of neglected tropical diseases. Though historically endemic to Latin America, it has lately spread to high-income countries due to human migration. At present, there are only two available drugs, nifurtimox and benznidazole, approved for tis treatment, both with considerable side-effects (which often result in treatment interruption) and limited efficacy in the chronic stage of the disease in adults. Drug repositioning involves finding novel therapeutic indications for known drugs, including approved, withdrawn, abandoned and investigational drugs. It is today a broadly applied approach to develop innovative medications, since indication shifts are built on existing safety, ADME and manufacturing information, thus greatly shortening development timeframes. Drug repositioning has been signaled as a particularly interesting strategy to search for new therapeutic solutions for neglected and rare conditions, which traditionally present limited commercial interest and are mostly covered by the public sector and non-for-profit initiatives and organizations. Here, we review the applications of computer-aided technologies as systematic approaches to drug repositioning in the field of Chagas disease. In silico screening represents the most explored approach, whereas other rational methods such as network-based and signature-based approximations have still not been applied.

PMID: 31622200 [PubMed - as supplied by publisher]

Captopril and Spironolactone Can Attenuate Diabetic Nephropathy in Wistar Rats by Targeting microRNA-192 and microRNA-29a/b/c.

DNA Cell Biol. 2019 Oct;38(10):1134-1142

Authors: Ebadi Z, Moradi N, Kazemi Fard T, Balochnejadmojarrad T, Chamani E, Fadaei R, Fallah S

Abstract
Diabetes mellitus is a complicated metabolic disease characterized by hyperglycemia. Diabetic nephropathy (DN) is a progressive kidney disease, which results in mortality in diabetic patients. The present study was designed to investigate the effect of applying spironolactone (S), captopril (C), and their combination (S+C) on some renal performance indices and microRNAs' (miRNAs) expression. A total of 35 two-month-old male Wistar rats were provided for the study. Intraperitoneal injection of freshly dissolved streptozotocin (60 mg/kg) in cold citrate buffer was used to induce diabetes. Blood samples were examined through calorimetry to assess serum concentrations of glucose, blood urea nitrogen (BUN), and creatinine. To measure the microalbuminuria and transforming growth factor-β (TGF-β) levels and to evaluate the miRNAs expression levels of the kidney tissue, the ELISA method and the real-time PCR were used. The obtained results serve as in vivo evidence for the positive relationship between miR-192 and TGF-β levels in the DN rats. A significant increase and decrease were found for miR-29a/b/c and the miR-192 expression of DN after treatment with S, C, and S+C. TGF-β levels and microalbuminuria of diabetic rats also increased. The results obtained from this research study suggest that S, C, and S + C can improve DN by targeting miR-192 and miR-29 family and changing their expression. These findings suggest that miR-192 and miRs-29a/b/c can be potential targets for DN remediation.

PMID: 31433203 [PubMed - indexed for MEDLINE]

Evaluation of Current and Emerging Antimalarial Medicines for Inhibition of Toxoplasma gondii Growth in Vitro.

ACS Infect Dis. 2018 08 10;4(8):1264-1274

Authors: Radke JB, Burrows JN, Goldberg DE, Sibley LD

Abstract
Toxoplasma gondii is a common zoonotic infection of humans, and estimates indicate that 1-2 billion people are chronically infected. Although largely asymptomatic, chronic infection poses risk of serious disease due to reactivation should immunity decline. Current therapies for toxoplasmosis only control acute infection caused by actively proliferating tachyzoites but do not eradicate the chronic tissue cyst stages. As well, there are considerable adverse side effects of the most commonly used therapy of combined sulfadiazine and pyrimethamine. Targeting the folate pathway is also an effective treatment for malaria, caused by the related parasites Plasmodium spp., suggesting common agents might be used to treat both infections. Here, we evaluated currently approved and newly emerging medicines for malaria to determine if such compounds might also prove useful for treating toxoplasmosis. Surprisingly, the majority of antimalarial compounds being used currently or in development for treatment of malaria were only modestly effective at inhibiting in vitro growth of T. gondii tachyzoites. These findings suggest that many essential processes in P. falciparum that are targeted by antimalarial compounds are either divergent or nonessential in T. gondii, thus limiting options for repurposing of current antimalarial medicines for toxoplasmosis.

PMID: 29998728 [PubMed - indexed for MEDLINE]

6 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"drug repositioning" OR "drug repurposing"

These pubmed results were generated on 2019/10/17

PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

6 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"drug repositioning" OR "drug repurposing"

These pubmed results were generated on 2019/10/17

PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Repurposing of known drugs for leishmaniasis treatment using bioinformatic predictions, in vitro validations and pharmacokinetic simulations.

J Comput Aided Mol Des. 2019 Oct 14;:

Authors: Bustamante C, Ochoa R, Asela C, Muskus C

Abstract
Leishmaniasis is a neglected tropical disease caused by Leishmania parasites and is associated to more than 1.3 million cases annually. Some of the pharmacological options for treating the disease are pentavalent antimonials, pentamidine, miltefosine, and amphotericin B. However, all are associated with a wide range of adverse effects and contraindications, as well as resistance from the parasite. In the present study, we looked for pharmacological alternatives to treat leishmaniasis, with a focus on drug repurposing. This was done by detecting potential homologs between proteins targeted by approved drugs and proteins of the parasite. The proteins were analyzed using an interaction network, and the drugs were subjected to in vitro evaluations and pharmacokinetics simulations to compare probable plasma concentrations with the effective concentrations detected experimentally. This strategy yielded a list of 33 drugs with potential anti-Leishmania activity, and more than 80 possible protein targets in the parasite. From the drugs tested, two reported high in vitro activity (perphenazine EC50 = 1.2 µg/mL and rifabutin EC50 = 8.5 µg/mL). These results allowed us to propose these drugs as candidates for further in vivo studies and evaluations of the effectiveness on their topical forms.

PMID: 31612362 [PubMed - as supplied by publisher]

Dihydroartemisinin up-regulates VE-cadherin expression in human renal glomerular endothelial cells.

J Cell Mol Med. 2018 03;22(3):2028-2032

Authors: Li L, Chen X, Dong F, Liu Q, Zhang C, Xu D, Allen TD, Liu J

Abstract
The antimalarial agent dihydroartemisinin (DHA) has been shown to be anti-inflammatory. In this study, we found that DHA increased the expression of the junctional protein vascular endothelial (VE)-cadherin in human renal glomerular endothelial cells. In addition, DHA inhibited TGF-β RI-Smad2/3 signalling and its downstream effectors SNAIL and SLUG, which repress VE-cadherin gene transcription. Correspondingly, DHA decreased the binding of SNAIL and SLUG to the VE-cadherin promoter. Together, our results suggest an effect of DHA in regulating glomerular permeability by elevation of VE-cadherin expression.

PMID: 29193726 [PubMed - indexed for MEDLINE]

8 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"drug repositioning" OR "drug repurposing"

These pubmed results were generated on 2019/10/15

PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Adapalene inhibits ovarian cancer ES-2 cells growth by targeting glutamic-oxaloacetic transaminase 1.

Bioorg Chem. 2019 Sep 26;93:103315

Authors: Wang Q, Zhang Q, Luan S, Yang K, Zheng M, Li K, Chen L, Li H

Abstract
Glutamic-oxaloacetic transaminase 1 (GOT1) regulates cellular metabolism through coordinating the utilization of carbohydrates and amino acids to meet nutrient requirements for sustained proliferation. As such, the GOT1 inhibitor may provide a new strategy for the treatment of various cancers. Adapalene has been approved by FDA for the treatment of acne, pimples and pustules, and it may also contribute to the adjunctive therapy for advanced stages of liver and colorectal cancers. In this work, we first examined the enzyme inhibition of over 500 compounds against GOT1 in vitro. As a result, Adapalene effectively inhibited GOT1 enzyme in a non-competitive manner. MST and DARTS assay further confirmed the high affinity between Adapalene and GOT1. Furthermore, the growth and migration of ovarian cancer ES-2 cells were obviously inhibited by the treatment of Adapalene. And it induced the apoptosis of ES-2 cells according to Western blot and Hoechst 33258 straining. In addition, molecular docking demonstrated that Adapalene coordinated in an allosteric site of GOT1 with low binding energy. Furthermore, knockdown of GOT1 in ES-2 cells decreased their anti-proliferative sensitivity to Adapalene. Together, our data strongly suggest Adapalene, as a GOT1 inhibitor, could be regarded as a potential drug candidate for ovarian cancer therapy.

PMID: 31605927 [PubMed - as supplied by publisher]

Chemoprevention agents for melanoma: A path forward into phase 3 clinical trials.

Cancer. 2019 01 01;125(1):18-44

Authors: Jeter JM, Bowles TL, Curiel-Lewandrowski C, Swetter SM, Filipp FV, Abdel-Malek ZA, Geskin LJ, Brewer JD, Arbiser JL, Gershenwald JE, Chu EY, Kirkwood JM, Box NF, Funchain P, Fisher DE, Kendra KL, Marghoob AA, Chen SC, Ming ME, Albertini MR, Vetto JT, Margolin KA, Pagoto SL, Hay JL, Grossman D, Ellis DL, Kashani-Sabet M, Mangold AR, Markovic SN, Nelson KC, Powers JG, Robinson JK, Sahni D, Sekulic A, Sondak VK, Wei ML, Zager JS, Dellavalle RP, Thompson JA, Weinstock MA, Leachman SA, Cassidy PB

Abstract
Recent progress in the treatment of advanced melanoma has led to unprecedented improvements in overall survival and, as these new melanoma treatments have been developed and deployed in the clinic, much has been learned about the natural history of the disease. Now is the time to apply that knowledge toward the design and clinical evaluation of new chemoprevention agents. Melanoma chemoprevention has the potential to reduce dramatically both the morbidity and the high costs associated with treating patients who have metastatic disease. In this work, scientific and clinical melanoma experts from the national Melanoma Prevention Working Group, composed of National Cancer Trials Network investigators, discuss research aimed at discovering and developing (or repurposing) drugs and natural products for the prevention of melanoma and propose an updated pipeline for translating the most promising agents into the clinic. The mechanism of action, preclinical data, epidemiological evidence, and results from available clinical trials are discussed for each class of compounds. Selected keratinocyte carcinoma chemoprevention studies also are considered, and a rationale for their inclusion is presented. These data are summarized in a table that lists the type and level of evidence available for each class of agents. Also included in the discussion is an assessment of additional research necessary and the likelihood that a given compound may be a suitable candidate for a phase 3 clinical trial within the next 5 years.

PMID: 30281145 [PubMed - indexed for MEDLINE]

Repurposing ciclopirox as a pharmacological chaperone in a model of congenital erythropoietic porphyria.

Sci Transl Med. 2018 09 19;10(459):

Authors: Urquiza P, Laín A, Sanz-Parra A, Moreno J, Bernardo-Seisdedos G, Dubus P, González E, Gutiérrez-de-Juan V, García S, Eraña H, San Juan I, Macías I, Ben Bdira F, Pluta P, Ortega G, Oyarzábal J, González-Muñiz R, Rodríguez-Cuesta J, Anguita J, Díez E, Blouin JM, de Verneuil H, Mato JM, Richard E, Falcón-Pérez JM, Castilla J, Millet O

Abstract
Congenital erythropoietic porphyria is a rare autosomal recessive disease produced by deficient activity of uroporphyrinogen III synthase, the fourth enzyme in the heme biosynthetic pathway. The disease affects many organs, can be life-threatening, and currently lacks curative treatments. Inherited mutations most commonly reduce the enzyme's stability, altering its homeostasis and ultimately blunting intracellular heme production. This results in uroporphyrin by-product accumulation in the body, aggravating associated pathological symptoms such as skin photosensitivity and disfiguring phototoxic cutaneous lesions. We demonstrated that the synthetic marketed antifungal ciclopirox binds to the enzyme, stabilizing it. Ciclopirox targeted the enzyme at an allosteric site distant from the active center and did not affect the enzyme's catalytic role. The drug restored enzymatic activity in vitro and ex vivo and was able to alleviate most clinical symptoms of congenital erythropoietic porphyria in a genetic mouse model of the disease at subtoxic concentrations. Our findings establish a possible line of therapeutic intervention against congenital erythropoietic porphyria, which is potentially applicable to most of deleterious missense mutations causing this devastating disease.

PMID: 30232228 [PubMed - indexed for MEDLINE]

Repurposing drugs to target the malaria parasite unfolding protein response.

Sci Rep. 2018 07 09;8(1):10333

Authors: Chen Y, Murillo-Solano C, Kirkpatrick MG, Antoshchenko T, Park HW, Pizarro JC

Abstract
Drug resistant Plasmodium falciparum parasites represent a major obstacle in our efforts to control malaria, a deadly vector borne infectious disease. This situation creates an urgent need to find and validate new drug targets to contain the spread of the disease. Several genes associated with the unfolded protein response (UPR) including Glucose-regulated Protein 78 kDa (GRP78, also known as BiP) have been deemed potential drug targets. We explored the drug target potential of GRP78, a molecular chaperone that is a regulator of the UPR, for the treatment of P. falciparum parasite infection. By screening repurposed chaperone inhibitors that are anticancer agents, we showed that GRP78 inhibition is lethal to drug-sensitive and -resistant P. falciparum parasite strains in vitro. We correlated the antiplasmodial activity of the inhibitors with their ability to bind the malaria chaperone, by characterizing their binding to recombinant parasite GRP78. Furthermore, we determined the crystal structure of the ATP binding domain of P. falciparum GRP78 with ADP and identified structural features unique to the parasite. These data suggest that P. falciparum GRP78 can be a valid drug target and that its structural differences to human GRP78 emphasize potential to generate parasite specific compounds.

PMID: 29985421 [PubMed - indexed for MEDLINE]

PDE3A inhibitor anagrelide activates death signaling pathway genes and synergizes with cell death-inducing cytokines to selectively inhibit cancer cell growth.

Am J Cancer Res. 2019;9(9):1905-1921

Authors: An R, Liu J, He J, Wang F, Zhang Q, Yu Q

Abstract
We performed a drug repurposing screening of a US Food and Drug Administration (FDA)-approved drug compound library and identified Anagrelide (ANA), a known phosphodiesterase 3A (PDE3A) inhibitor, that selectively and potently inhibited the growth of cancer cells. However, inactivation of PDE3A or knocking-down its gene expression did not inhibit cancer cell growth. It was the interaction of ANA with PDE3A that created a new function of PDE3A to alter the activities of another unknown function protein SLFN12 to cause the inhibition of cancer cell growth. The expressions of both PDE3A and SLFN12 were required for ANA to inhibit cancer cell growth. Depletion of PDE3A or SLFN12 led to ANA resistance. Furthermore, the effects of ANA on different cancer cells were different depending on the expression levels of PDE3A and SLFN12, causing G0/G1 cell cycle arrest in the cells expressing lower levels of SLFN12, but apoptosis in the cells expressing higher levels of the two proteins. Further investigation into the molecular mechanisms of the ANA-induced cell cycle arrest and apoptosis identified a set of cell cycle and apoptosis-related genes whose expressions were altered by ANA treatment. ANA also synergized with the cell death-inducing cytokines IFN-α, IFN-γ, TNF-α, or TRAIL, which regulated the same set of genes as ANA did, to induce apoptosis of the cancer cells. Our study uncovered new activities, functions, and mechanisms of ANA and SLFN12 and provided a diagnosis method to precisely use ANA as an anti-cancer drug. It also revealed PDE3A and SLFN12 as new anti-cancer drug targets for developing novel anti-cancer therapies.

PMID: 31598394 [PubMed]