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Asnake, Solomon
Publications (10 of 13) Show all publications
Dong, J., Zhang, J., Li, Z., Asnake, S., Zhang, D., Olsson, P.-E. & Zhao, G. (2019). Design, synthesis, and biological evaluation of 2-(5-methyl-1H-pyrazol-1-yl) acetamide derivatives as androgen receptor antagonists. Medicinal Chemistry Research, 28(3), 380-386
Open this publication in new window or tab >>Design, synthesis, and biological evaluation of 2-(5-methyl-1H-pyrazol-1-yl) acetamide derivatives as androgen receptor antagonists
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2019 (English)In: Medicinal Chemistry Research, ISSN 1054-2523, E-ISSN 1554-8120, Vol. 28, no 3, p. 380-386Article in journal (Refereed) Published
Abstract [en]

Androgen receptor (AR) signaling is often activated in prostate cancer (PCa) cells, and blockage of this signaling by AR antagonists is an important strategy in PCa therapy. In this study, we designed and synthesized a series of 2-(5-methyl-1H-pyrazol-1-yl) acetamide derivatives, and evaluated their biological activities. AR luciferase reporter assay revealed compound 6f (59.7%) as a potent AR antagonist. Some compounds in this series showed higher anti-proliferative activity against LNCaP cells than Bicalutamide (IC50=35.0M), especially 6g with IC50 value of 13.6 mu M.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Androgen receptor, Prostate cancer, Antagonists, Pyrazole derivatives
National Category
Pharmacology and Toxicology Cancer and Oncology
Identifiers
urn:nbn:se:oru:diva-73118 (URN)10.1007/s00044-019-02291-y (DOI)000459449600013 ()2-s2.0-85060553900 (Scopus ID)
Funder
Knowledge Foundation, 201550084
Note

Funding Agencies:

National Natural Science Foundation of China  21272140 

Key Research and Development Project of Shandong Province  2017CXGC1401 

Available from: 2019-03-14 Created: 2019-03-14 Last updated: 2019-03-14Bibliographically approved
Asnake, S., Modig, C. & Olsson, P.-E. (2019). Species differences in ligand interaction and activation of estrogen receptors in fish and human. Journal of Steroid Biochemistry and Molecular Biology, Article ID 105450.
Open this publication in new window or tab >>Species differences in ligand interaction and activation of estrogen receptors in fish and human
2019 (English)In: Journal of Steroid Biochemistry and Molecular Biology, ISSN 0960-0760, E-ISSN 1879-1220, article id 105450Article in journal (Refereed) Epub ahead of print
Abstract [en]

Estrogen receptor (ER) sequences vary between species and this suggests that there are differences in the ligand-specificity, leading to species-specific effects. This would indicate that it is not possible to generalize effects across species. In this study, we investigated the differences in activation potencies and binding affinities of ER´s alpha (α) and beta (β) in human, zebrafish and sea bream to elucidate species differences in response to estradiol, estrone, estriol and methyltestosterone. In vitro analysis showed that estradiol had the highest activity for all the ER´s except for human ERβ and seabream ERβ2. Alignment of the ligand binding domain and ligand binding pocket (LBP) residues of the three species showed that different residues were involved in the LBPs which led to differences in pocket volume, affected binding affinity and orientation of the ligands. By combining in silico and in vitro results, it was possible to identify the ligand specificities of ER´s. The results demonstrated that the human ER´s show lower resolution in ligand-dependent activation, suggesting higher promiscuity, than the zebrafish and seabream ER´s. These results show species-specificity of ER´s and suggest that species-specific differences must be taken into consideration when studying different exposure scenarios.

Place, publisher, year, edition, pages
Pergamon Press, 2019
Keywords
In silico, ligand binding pocket, ligand resolution, ligand specificity, species-specific
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:oru:diva-75906 (URN)10.1016/j.jsbmb.2019.105450 (DOI)31437548 (PubMedID)
Available from: 2019-09-09 Created: 2019-09-09 Last updated: 2019-09-09Bibliographically approved
Zhang, D., Asnake, S., Zhang, J., Olsson, P.-E. & Zhao, G. (2018). Discovery of novel 5-methyl-1H-pyrazole derivatives as potential anti-prostate cancer agents: design, synthesis, molecular modeling and biological evaluation. Chemical Biology and Drug Design, 91(6), 1113-1124
Open this publication in new window or tab >>Discovery of novel 5-methyl-1H-pyrazole derivatives as potential anti-prostate cancer agents: design, synthesis, molecular modeling and biological evaluation
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2018 (English)In: Chemical Biology and Drug Design, ISSN 1747-0277, E-ISSN 1747-0285, Vol. 91, no 6, p. 1113-1124Article in journal (Refereed) Published
Abstract [en]

Androgen receptor (AR) signaling functions as a core driving force for the progression of prostate cancer (PCa), and AR has been proved to be an effective therapeutic target even for castration resistant prostate cancer (CRPC). Herein, structural modification via a fragments splicing strategy was performed based on two lead compounds T3 and 10e, leading to the discovery of a series of 5-methyl-1H-pyrazole derivatives. AR reporter gene assay revealed compounds A13 and A14 as potent AR antagonists. Some of the compounds in this series inhibited growth of PCa LNCaP cells more efficiently than enzalutamide. A13 and A14 also showed improved metabolic stability comparing with 10e in human liver microsomes.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
androgen receptor, AR antagonist, luciferase reporter gene assay, prostate cancer, pyrazole derivative
National Category
Cancer and Oncology Cell and Molecular Biology
Identifiers
urn:nbn:se:oru:diva-64844 (URN)10.1111/cbdd.13173 (DOI)000431974400006 ()29388326 (PubMedID)2-s2.0-85042562810 (Scopus ID)
Note

Funding Agency:

National Natural Science Foundation of China  21272140

Available from: 2018-02-07 Created: 2018-02-07 Last updated: 2018-08-20Bibliographically approved
Kharlyngdoh, J. B., Asnake, S., Pradhan, A. & Olsson, P.-E. (2016). TBECH, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane, alters androgen receptor regulation in response to mutations associated with prostate cancer. Toxicology and Applied Pharmacology, 307, 91-101
Open this publication in new window or tab >>TBECH, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane, alters androgen receptor regulation in response to mutations associated with prostate cancer
2016 (English)In: Toxicology and Applied Pharmacology, ISSN 0041-008X, E-ISSN 1096-0333, Vol. 307, p. 91-101Article in journal (Refereed) Published
Abstract [en]

Point mutations in the AR ligand-binding domain (LBD) can result in altered AR structures leading to changes of ligand specificity and functions. AR mutations associated to prostate cancer (PCa) have been shown to result in receptor activation by non-androgenic substances and anti-androgenic drugs. Two AR mutations known to alter the function of anti-androgens are the ART877A mutation, which is frequently detected mutation in PCa tumors and the ARW741C that is rare and has been derived in vitro following exposure of cells to the anti-androgen bicalutamide. AR activation by non-androgenic environmental substances has been suggested to affect PCa progression. In the present study we investigated the effect of AR mutations (ARW741C and ART877A) on the transcriptional activation following exposure of cells to an androgenic brominated flame retardant, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane (TBECH, also named DBE-DBCH). The AR mutations resulted in higher interaction energies and increased transcriptional activation in response to TBECH diastereomer exposures. The ART877A mutation rendered AR highly responsive to low levels of DHT and TBECH and led to increased AR nuclear translocation. Gene expression analysis showed a stronger induction of AR target genes in LNCaP cells (ART877A) compared to T-47D cells (ARWT) following TBECH exposure. Furthermore, AR knockdown experiments confirmed the AR dependency of these responses. The higher sensitivity of ART877A and ARW741C to low levels of TBECH suggests that cells with these AR mutations are more susceptible to androgenic endocrine disrupters.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Steroid hormone, endocrine disrupting compounds, nuclear localization, receptor, nuclear localization
National Category
Cell Biology Pharmacology and Toxicology
Identifiers
urn:nbn:se:oru:diva-51471 (URN)10.1016/j.taap.2016.07.018 (DOI)000382417400009 ()27473015 (PubMedID)2-s2.0-84980328031 (Scopus ID)
Funder
Knowledge Foundation
Note

Funding Agency:

Örebro University, Sweden 

Available from: 2016-08-05 Created: 2016-08-02 Last updated: 2018-01-10Bibliographically approved
Banjop-Kharlygdoh, J., Pradhan, A., Asnake, S., Walstad, A., Ivarsson, P. & Olsson, P.-E. (2015). Identification of a group of brominated flame retardants as novel androgen receptor antagonists and potential neuronal and endocrine disrupters. Environment International, 74, 60-70
Open this publication in new window or tab >>Identification of a group of brominated flame retardants as novel androgen receptor antagonists and potential neuronal and endocrine disrupters
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2015 (English)In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 74, p. 60-70Article in journal (Refereed) Published
Abstract [en]

Brominated flame-retardants (BFRs) are used in industrial products to reduce the risk of fire. However, their continuous release into the environment is a concern as they are often persistent, bioaccumulating and toxic. Information on the impact these compounds have on human health and wildlife is limited and only a few of them have been identified to disrupt hormone receptor functions. In the present study we used in silico modeling to determine the interactions of selected BFRs with the human androgen receptor (AR). Three compounds were found to dock into the ligand-binding domain of the human AR and these were further tested using in vitro analysis. Allyl 2,4,6-tribromophenyl ether (ATE), 2-bromoallyl 2,4,6-tribromophenyl ether (BATE) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) were observed to act as AR antagonists. These BFRs have recently been detected in the environment, in house dust and in aquatic animals. The compounds have been detected at high concentrations in both blubber and brain of seals and we therefore also assessed their impact on the expression of L-type amino acid transporter system (LAT) genes, that are needed for amino acid uptake across the blood-brain barrier, as disruption of LAT gene function has been implicated in several brain disorders. The three BFRs down-regulated the expression of AR target genes that encode for prostate specific antigen (PSA), 5. α-reductases and β-microseminoprotein. The potency of PSA inhibition was of the same magnitude as the common prostate cancer drugs, demonstrating that these compounds are strong AR antagonists. Western blot analysis of AR protein showed that ATE, BATE and DPTE decreased the 5. α-dihydrotestosterone-induced AR protein levels, further confirming that these BFRs act as AR antagonists. The transcription of the LAT genes was altered by the three BFRs, indicating an effect on amino-acid uptake across cellular membranes and blood-brain barrier. This study demonstrated that ATE, BATE and DPTE are potent AR antagonists and the alterations in LAT gene transcription suggest that these compounds can affect neuronal functions and should be considered as potential neurotoxic and endocrine disrupting compounds.

Keywords
Gene regulation; Human; PSA; LAT
National Category
Environmental Sciences
Research subject
Biology
Identifiers
urn:nbn:se:oru:diva-41508 (URN)10.1016/j.envint.2014.09.002 (DOI)000346681700008 ()25454221 (PubMedID)2-s2.0-84908626070 (Scopus ID)
Funder
Knowledge Foundation, 20110183
Note

Funding Agency:

Örebro University J61900

Available from: 2015-01-14 Created: 2015-01-14 Last updated: 2017-12-05Bibliographically approved
Pradhan, A., Asnake, S., Kharlyngdoh, J. B., Modig, C. & Olsson, P.-E. (2015). In silico and biological analysis of anti-androgen activity of the brominated flame retardants ATE, BATE and DPTE in zebrafish. Chemico-Biological Interactions, 233, 35-45
Open this publication in new window or tab >>In silico and biological analysis of anti-androgen activity of the brominated flame retardants ATE, BATE and DPTE in zebrafish
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2015 (English)In: Chemico-Biological Interactions, ISSN 0009-2797, E-ISSN 1872-7786, Vol. 233, p. 35-45Article in journal (Refereed) Published
Abstract [en]

The brominated flame retardants (BFRs) 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH or DBE-DCBH) and allyl 2,4,6-tribromophenyl ether (ATE or TBP-AE) are alternative BFRs that have been introduced to replace banned BFRs. TBECH is a potential endocrine disrupter in human, chicken and zebrafish and in a recent study we showed that ATE, along with the structurally similar BFR 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE or TBP-DBPE) and its metabolite 2-bromoallyl 2,4,6-tribromophenyl ether (BATE or TBP-BAE) are potential endocrine and neuronal disrupters in human. In this study we analyzed ATE, BATE and DPTE for zebrafish androgen receptor (zAR) modulating properties. In silico analysis with two softwares, Molecular Operating Environment (MOE) and Internal Coordinate Mechanics (ICM), showed that ATE, BATE and DPTE bind to zAR. In vitro AR activation assay revealed that these three BFRs down-regulate 11-ketotestosterone (KT) mediated zAR activation. Exposure to 10 mu M DPTE resulted in reduced hatching success and like TBECH, BATE and DPTE at 10 mu M also had teratogenic properties with 20% and 50% back-bone curvature respectively. Gene transcription analysis in zebrafish embryos as well as in juveniles showed down-regulation of the androgen receptor and androgen response genes, which further support that these BFRs are androgen antagonists and potential endocrine disrupting compounds. Genes involved in steroidogenesis were also down-regulated by these BFRs. In view of this, the impact of these BFRs on humans and wildlife needs further analysis.

Keywords
Gene regulation; Steroidogenesis; TBP-AE; TBP-BAE; TBP-DBPE; Teratogenesis
National Category
Biological Sciences
Research subject
Biology
Identifiers
urn:nbn:se:oru:diva-44811 (URN)10.1016/j.cbi.2015.03.023 (DOI)000354139600004 ()25818047 (PubMedID)2-s2.0-84926156248 (Scopus ID)
Funder
Knowledge Foundation
Note

Funding Agency:

Örebro University

Available from: 2015-06-03 Created: 2015-06-03 Last updated: 2017-10-18Bibliographically approved
Asnake, S. (2015). Interaction of brominated flame retardants with the chicken and zebrafish androgen receptors. (Doctoral dissertation). Örebro: Örebro university
Open this publication in new window or tab >>Interaction of brominated flame retardants with the chicken and zebrafish androgen receptors
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The survival of organisms depends on their ability to use different signaling pathways to adapt to the environment. The endocrine system consists of glands that release hormones to the blood stream. Male reproductive functions are regulated by androgens through interactions with the androgen receptor (AR). AR has been characterized in chicken and zebrafish where they use testosterone and 11-ketotestosterone as their primary androgens, respectively. AR function has been disturbed by different endocrine disrupting compounds (EDCs) present in the environment causing detrimental effects on avian and fish species. Brominated flame retardants (BFRs) are a group of EDCs that are ubiquitous in the environment. Molecular modeling techniques using computer simulations such as docking and molecular dynamics are a useful tool in the identification of EDCs. The capacity to test thousands of compounds at once has helped in the early identification of EDCs that interact with AR. Two groups of BFRs, the 1,2-dibromo-4- cyclohexane diastereomers (TBECH) and the compounds synthesized from 2, 4, 6-tribromophenol, allyl 2,4,6-tribromophenyl ether (ATE), 2-bromoallyl 2,4,6- tribromophenyl ether (BATE) and 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE) interact and alter AR activity in human in vitro studies. As models for avian and fish species, chicken and zebrafish were used to test these BFRs. TBECH diastereomers were able to bind to the AR, estrogen receptors and thyroid receptors in the chicken and to the AR in zebrafish. ATE, BATE and DPTE were also able to interact with the chicken AR and zebrafish AR. Activation studies using cell lines showed that TBECH diastereomers acted as agonists to the cAR and zAR while ATE, BATE and DPTE acted as antagonists. The BFRs also altered multiple signaling pathways such as the apoptotic, antiapoptotic, immune, drug metabolizing and DNA methylation systems and in vivo studies resulted in physiological effects on zebrafish.

Place, publisher, year, edition, pages
Örebro: Örebro university, 2015. p. 70
Series
Örebro Studies in Life Science ; 12
Keywords
DBE-DBCH, TBP-AE, TBP-BAE, TBP-DBPE, gene transcription
National Category
Biological Sciences
Research subject
Biology
Identifiers
urn:nbn:se:oru:diva-42881 (URN)978-91-7529-067-6 (ISBN)
Public defence
2015-04-29, Hörsalen, Musikhögskolan, Örebro universitet, Fakultetsgatan 1, Örebro, 10:00 (English)
Opponent
Supervisors
Available from: 2015-02-23 Created: 2015-02-23 Last updated: 2017-10-17Bibliographically approved
Asnake, S., Pradhan, A., Kharlyngdoh, J. B., Modig, C. & Olsson, P.-E. (2015). The brominated flame retardants TBP-AE and TBP-DBPE antagonize the chicken androgen receptor and act as potential endocrine disrupters in chicken LMH cells. Toxicology in Vitro, 29(8), 1993-2000
Open this publication in new window or tab >>The brominated flame retardants TBP-AE and TBP-DBPE antagonize the chicken androgen receptor and act as potential endocrine disrupters in chicken LMH cells
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2015 (English)In: Toxicology in Vitro, ISSN 0887-2333, E-ISSN 1879-3177, Vol. 29, no 8, p. 1993-2000Article in journal (Refereed) Published
Abstract [en]

Increased exposure of birds to endocrine disrupting compounds has resulted in developmental and reproductive dysfunctions. We have recently identified the flame retardants, ally1-2,4,6-tribromophenyl ether (TBP-AE), 2-3-dibromopropy1-2,4,6-tribromophenyl ether (TBP-DBPE) and the TBP-DBPE metabolite 2-bromoallyI-2,4,6-tribromophenyl ether (TBP-BAE) as antagonists to both the human androgen receptor (AR) and the zebrafish AR. In the present study, we aimed at determining whether these compounds also interact with the chicken AR. In silico modeling studies showed that TBP-AE, TBP-BAE and TBP-DBPE were able to dock into to the chicken AR ligand-binding pocket. In vitro transfection assays revealed that all three brominated compounds acted as chicken AR antagonists, inhibiting testosterone induced AR activation. In addition, qRT-PCR studies confirmed that they act as AR antagonists and demonstrated that they also alter gene expression patterns of apoptotic, anti-apoptotic, drug metabolizing and amino acid transporter genes. These studies, using chicken LMH cells, suggest that TBP-AE, TBP-BAE and TBP-DBPE are potential endocrine disrupters in chicken.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
EDC, Avian, Signaling pathways, ATE, BATE, DPTE, DBE-DBCH, TBECH
National Category
Pharmacology and Toxicology Biological Sciences
Research subject
Biology
Identifiers
urn:nbn:se:oru:diva-47080 (URN)10.1016/j.tiv.2015.08.009 (DOI)000364892000004 ()26318274 (PubMedID)2-s2.0-84940502384 (Scopus ID)
Funder
Swedish Research Council, 20110183
Note

Funding Agency:

Örebro University J61900

Available from: 2015-12-15 Created: 2015-12-15 Last updated: 2018-01-10Bibliographically approved
Asnake, S., Pradhan, A., Banjop-Kharlyngdoh, J., Modig, C. & Olsson, P.-E. (2014). 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane (TBECH)-mediated steroid hormone receptor activation and gene regulation in chicken LMH cells. Environmental Toxicology and Chemistry, 33(4), 891-899
Open this publication in new window or tab >>1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane (TBECH)-mediated steroid hormone receptor activation and gene regulation in chicken LMH cells
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2014 (English)In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 33, no 4, p. 891-899Article in journal (Refereed) Published
Abstract [en]

The incorporation of brominated flame retardants into industrial and household appliances has increased their occurrence in the environment, resulting in deleterious effects on wildlife. With the increasing restraints on available compounds, there has been a shift to using brominated flame retardants that has seen the production of alternative brominated flame retardants such as 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane (TBECH), which has been detected in the environment. In previous in silico and in vitro studies the authors have shown that TBECH can activate both the human androgen receptor (hAR) and the zebrafish AR (zAR) suggesting that it is a potential endocrine disruptor. The present study was aimed at determining the interaction of TBECH with the chicken AR (cAR). In the present study, TBECH bound to cAR, but in vitro activation assay studies using the chicken LMH cell line showed it had a potency of only 15% compared with testosterone. Sequence difference between ARs from different species may contribute to the different responses to TBECH. Further quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) analysis showed that TBECH interacted with and altered the expression of both thyroid receptors and estrogen receptors. In addition, the qRT-PCR analysis showed that TBECH altered the transcription pattern of genes involved in inflammatory, apoptotic, proliferative, DNA methylation, and drug-metabolizing pathways. This demonstrates that TBECH, apart from activating cAR, can also influence multiple biological pathways in the chicken.

Place, publisher, year, edition, pages
Hoboken: Wiley-Blackwell, 2014
Keywords
Endocrine disruptor, Diastereomer, Enantiomer, Quantitative polymerase chain reaction (qPCR), Gene regulation
National Category
Environmental Sciences
Research subject
Enviromental Science; Biology
Identifiers
urn:nbn:se:oru:diva-34941 (URN)10.1002/etc.2509 (DOI)000333538700020 ()2-s2.0-84897431931 (Scopus ID)
Funder
Swedish Research Council
Note

Funding Agency:

Örebro University

Available from: 2014-05-05 Created: 2014-05-05 Last updated: 2017-12-05Bibliographically approved
Pradhan, A., Kharlyngdoh, J. B., Asnake, S. & Olsson, P.-E. (2013). The brominated flame retardant TBECH activates the zebrafish (Danio rerio) androgen receptor, alters gene transcription and causes developmental disturbances. Aquatic Toxicology, 142, 63-72
Open this publication in new window or tab >>The brominated flame retardant TBECH activates the zebrafish (Danio rerio) androgen receptor, alters gene transcription and causes developmental disturbances
2013 (English)In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 142, p. 63-72Article in journal (Refereed) Published
Abstract [en]

Tetrabromoethylcyclohexane (TBECH) is a brominated flame retardant that has been shown to be a potent agonist to the human androgen receptor (AR). However, while it is present in the environment, it is not known if it interacts with AR from aquatic species. The present study was therefore aimed at improving our understanding of how TBECH affects aquatic animals using zebrafish as a model organism. In silica modeling demonstrated that TBECH diastereomers bind to the zebrafish androgen receptor (zAR) and in vitro and in vivo data showed that TBECH has androgenic properties. Deleterious effects of TBECH were studied on embryonic and juvenile zebrafish and qRT-PCR analysis in vitro and in vivo was performed to determine TBECH effects on gene regulation. TBECH was found to delay hatching at 1 mu M and 10 mu M doses while morphological abnormalities and juvenile mortality was observed at 10 mu M. The qRT-PCR analysis showed alterations of multiple genes involved in chondrogenesis (cartilage development), metabolism and stress response. Thus, TBECH induces androgenic activity and has negative effects on zebrafish physiology and therefore its impact on the environment should be carefully monitored. (C) 2013 Elsevier B.V. All rights reserved.

Keywords
Androgens, Endocrine, Endocrine disruptor, Gene regulation
National Category
Biological Sciences
Identifiers
urn:nbn:se:oru:diva-32902 (URN)10.1016/j.aquatox.2013.07.018 (DOI)000328093900007 ()23958786 (PubMedID)
Funder
Knowledge Foundation
Available from: 2014-01-02 Created: 2014-01-02 Last updated: 2017-12-06Bibliographically approved
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