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Trinconi CT, Miguel DC, Silber AM, Brown C, Mina JGM, Denny PW, Heise N, Uliana SRB. Tamoxifen inhibits the biosynthesis of inositolphosphorylceramide in Leishmania. Int J Parasitol Drugs Drug Resist 2018; 8:475-487. [PMID: 30399513 PMCID: PMC6216108 DOI: 10.1016/j.ijpddr.2018.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/21/2018] [Accepted: 10/23/2018] [Indexed: 11/19/2022]
Abstract
Previous work from our group showed that tamoxifen, an oral drug that has been in use for the treatment of breast cancer for over 40 years, is active both in vitro and in vivo against several species of Leishmania, the etiological agent of leishmaniasis. Using a combination of metabolic labeling with [3H]-sphingosine and myo-[3H]-inositol, alkaline hydrolysis, HPTLC fractionations and mass spectrometry analyses, we observed a perturbation in the metabolism of inositolphosphorylceramides (IPCs) and phosphatidylinositols (PIs) after treatment of L. amazonensis promastigotes with tamoxifen, with a significant reduction in the biosynthesis of the major IPCs (composed of d16:1/18:0-IPC, t16:0/C18:0-IPC, d18:1/18:0-IPC and t16:0/20:0-IPC) and PIs (sn-1-O-(C18:0)alkyl -2-O-(C18:1)acylglycerol-3-HPO4-inositol and sn-1-O-(C18:0)acyl-2-O-(C18:1)acylglycerol-3-HPO4-inositol) species. Substrate saturation kinetics of myo-inositol uptake analyses indicated that inhibition of inositol transport or availability were not the main reasons for the reduced biosynthesis of IPC and PI observed in tamoxifen treated parasites. An in vitro enzymatic assay was used to show that tamoxifen was able to inhibit the Leishmania IPC synthase with an IC50 value of 8.48 μM (95% CI 7.68–9.37), suggesting that this enzyme is most likely one of the targets for this compound in the parasites. Tamoxifen alters the sphingolipid metabolism of L. amazonensis. Tamoxifen treated parasites show a significant reduction of IPC and PI species. Tamoxifen-treated parasites present a reduction of inositol transport. Tamoxifen is an inhibitor of L. major's IPC synthase in a micromolar range.
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Affiliation(s)
- Cristiana T Trinconi
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
| | - Danilo C Miguel
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
| | - Ariel M Silber
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil
| | - Christopher Brown
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK
| | - John G M Mina
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK
| | - Paul W Denny
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK
| | - Norton Heise
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Silvia R B Uliana
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, SP, 05508-000, Brazil.
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