scholarly journals Three Different Mutations in the DNA Topoisomerase 1B in Leishmania Infantum Contribute to Resistance to Antitumor Drug Topotecan

2021 ◽  
Author(s):  
Chloe Rosa-Teijeiro ◽  
Victoria Wagner ◽  
Audrey Corbeil ◽  
Ilda d'Annessa ◽  
Philippe Leprohon ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Large Subunit ◽  
Binding Pocket ◽  
Next Generation Sequencing Data ◽  
Whole Genome ◽  
Sequencing Data ◽  
Theoretical Approaches ◽  
In The Wild ◽  
Approved Drugs ◽  
Dynamics Simulations

Abstract BackgroundThe evolution of drug resistance is one of the biggest challenges in leishmaniasis and has prompted the need for new antileishmanial drugs. Repurposing of approved drugs is a faster and very attractive strategy that is gaining supporters worldwide. Different anticancer topoisomerase 1B (TOP1B) inhibitors have shown strong antileishmanial activity and promising selective indices, supporting the potential repurposing of these drugs. However, cancer cells and Leishmania share the ability to become rapidly resistant. The aim of this study was to complete a whole-genome exploration of the effects caused by exposure to topotecan in order to highlight the potential mechanisms deployed by Leishmania to favor its survival in the presence of a TOP1B inhibitor. MethodsWe used a combination of stepwise drug-resistance selection, whole-genome sequencing, functional validation, and theoretical approaches to explore the propensity of and potential mechanisms deployed by three independent clones of L. infantum to resist the action of TOP1B-inhibitor topotecan. ResultsWe demonstrated that L. infantum is capable of becoming resistant to high concentrations of topotecan without impaired growth ability. No gene deletions or amplifications were identified from the next-generation sequencing data in any of the three resistant lines, ruling out the overexpression of efflux pumps as the preferred mechanism of topotecan resistance. We identified three different mutations in the large subunit of the leishmanial TOP1B (Top1BF187Y, Top1BG191A and Top1BW232R). Overexpression of these mutated alleles in the wild-type background led to high levels of resistance to topotecan. Computational molecular dynamics simulations, in both covalent and non-covalent complexes, showed that these mutations have an effect on the arrangement of the catalytic pentad and on the interaction of these residues with surrounding amino acids and DNA. This altered architecture of the binding pocket results in decreased persistence of topotecan in the ternary complex. ConclusionsThis work helps elucidate the previously-unclear potential mechanisms of topotecan resistance in Leishmania by mutations in the large subunit of TOP1B and provides a valuable clue for the design of improved inhibitors to combat resistance in both leishmaniasis and cancer. Our data highlights the importance of including drug-resistance evaluation in drug-discovery cascades.

scholarly journals Three different mutations in the DNA topoisomerase 1B in Leishmania infantum contribute to resistance to antitumor drug topotecan

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Chloé Rosa-Teijeiro ◽  
Victoria Wagner ◽  
Audrey Corbeil ◽  
Ilda d’Annessa ◽  
Philippe Leprohon ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Large Subunit ◽  
Binding Pocket ◽  
Next Generation Sequencing Data ◽  
Whole Genome ◽  
Sequencing Data ◽  
Theoretical Approaches ◽  
In The Wild ◽  
Approved Drugs ◽  
Dynamics Simulations

Abstract Background The evolution of drug resistance is one of the biggest challenges in leishmaniasis and has prompted the need for new antileishmanial drugs. Repurposing of approved drugs is a faster and very attractive strategy that is gaining supporters worldwide. Different anticancer topoisomerase 1B (TOP1B) inhibitors have shown strong antileishmanial activity and promising selective indices, supporting the potential repurposing of these drugs. However, cancer cells and Leishmania share the ability to become rapidly resistant. The aim of this study was to complete a whole-genome exploration of the effects caused by exposure to topotecan in order to highlight the potential mechanisms deployed by Leishmania to favor its survival in the presence of a TOP1B inhibitor. Methods We used a combination of stepwise drug resistance selection, whole-genome sequencing, functional validation, and theoretical approaches to explore the propensity of and potential mechanisms deployed by three independent clones of L. infantum to resist the action of TOP1B inhibitor topotecan. Results We demonstrated that L. infantum is capable of becoming resistant to high concentrations of topotecan without impaired growth ability. No gene deletions or amplifications were identified from the next-generation sequencing data in any of the three resistant lines, ruling out the overexpression of efflux pumps as the preferred mechanism of topotecan resistance. We identified three different mutations in the large subunit of the leishmanial TOP1B (Top1BF187Y, Top1BG191A, and Top1BW232R). Overexpression of these mutated alleles in the wild-type background led to high levels of resistance to topotecan. Computational molecular dynamics simulations, in both covalent and non-covalent complexes, showed that these mutations have an effect on the arrangement of the catalytic pentad and on the interaction of these residues with surrounding amino acids and DNA. This altered architecture of the binding pocket results in decreased persistence of topotecan in the ternary complex. Conclusions This work helps elucidate the previously unclear potential mechanisms of topotecan resistance in Leishmania by mutations in the large subunit of TOP1B and provides a valuable clue for the design of improved inhibitors to combat resistance in both leishmaniasis and cancer. Our data highlights the importance of including drug resistance evaluation in drug discovery cascades. Graphical abstract

scholarly journals geno2pheno[ngs-freq]: a genotypic interpretation system for identifying viral drug resistance using next-generation sequencing data

2018 ◽  
Vol 46 (W1) ◽  
pp. W271-W277 ◽  
Author(s):  
Matthias Döring ◽  
Joachim Büch ◽  
Georg Friedrich ◽  
Alejandro Pironti ◽  
Prabhav Kalaghatgi ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Next Generation Sequencing ◽  
Next Generation Sequencing Data ◽  
Next Generation ◽  
Sequencing Data ◽  
Interpretation System ◽  
Generation Sequencing

scholarly journals Crystal structure of the human NK1 tachykinin receptor

2018 ◽  
Vol 115 (52) ◽  
pp. 13264-13269 ◽  
Author(s):  
Jie Yin ◽  
Karen Chapman ◽  
Lindsay D. Clark ◽  
Zhenhua Shao ◽  
Dominika Borek ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Substance P ◽  
Binding Pocket ◽  
Computational Docking ◽  
Tachykinin Receptor ◽  
Approved Drugs ◽  
Dynamics Simulations ◽  
Receptor Modulators ◽  
Further Development ◽  
G Protein Coupled

The NK1 tachykinin G-protein–coupled receptor (GPCR) binds substance P, the first neuropeptide to be discovered in mammals. Through activation of NK1R, substance P modulates a wide variety of physiological and disease processes including nociception, inflammation, and depression. Human NK1R (hNK1R) modulators have shown promise in clinical trials for migraine, depression, and emesis. However, the only currently approved drugs targeting hNK1R are inhibitors for chemotherapy-induced nausea and vomiting (CINV). To better understand the molecular basis of ligand recognition and selectivity, we solved the crystal structure of hNK1R bound to the inhibitor L760735, a close analog of the drug aprepitant. Our crystal structure reveals the basis for antagonist interaction in the deep and narrow orthosteric pocket of the receptor. We used our structure as a template for computational docking and molecular-dynamics simulations to dissect the energetic importance of binding pocket interactions and model the binding of aprepitant. The structure of hNK1R is a valuable tool in the further development of tachykinin receptor modulators for multiple clinical applications.

scholarly journals Drug resistance profile and clonality of Plasmodium falciparum parasites in Cape Verde: the 2017 malaria outbreak

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Silvania Da Veiga Leal ◽  
Daniel Ward ◽  
Susana Campino ◽  
Ernest Diez Benavente ◽  
Amy Ibrahim ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Family Members ◽  
Cape Verde ◽  
Whole Genome Sequencing Data ◽  
Whole Genome ◽  
Sequencing Data ◽  
High Level

Abstract Background Cape Verde is an archipelago located off the West African coast and is in a pre-elimination phase of malaria control. Since 2010, fewer than 20 Plasmodium falciparum malaria cases have been reported annually, except in 2017, when an outbreak in Praia before the rainy season led to 423 autochthonous cases. It is important to understand the genetic diversity of circulating P. falciparum to inform on drug resistance, potential transmission networks and sources of infection, including parasite importation. Methods Enrolled subjects involved malaria patients admitted to Dr Agostinho Neto Hospital at Praia city, Santiago island, Cape Verde, between July and October 2017. Neighbours and family members of enrolled cases were assessed for the presence of anti-P. falciparum antibodies. Sanger sequencing and real-time PCR was used to identify SNPs in genes associated with drug resistance (e.g., pfdhfr, pfdhps, pfmdr1, pfk13, pfcrt), and whole genome sequencing data were generated to investigate the population structure of P. falciparum parasites. Results The study analysed 190 parasite samples, 187 indigenous and 3 from imported infections. Malaria cases were distributed throughout Praia city. There were no cases of severe malaria and all patients had an adequate clinical and parasitological response after treatment. Anti-P. falciparum antibodies were not detected in the 137 neighbours and family members tested. No mutations were detected in pfdhps. The triple mutation S108N/N51I/C59R in pfdhfr and the chloroquine-resistant CVIET haplotype in the pfcrt gene were detected in almost all samples. Variations in pfk13 were identified in only one sample (R645T, E668K). The haplotype NFD for pfmdr1 was detected in the majority of samples (89.7%). Conclusions Polymorphisms in pfk13 associated with artemisinin-based combination therapy (ACT) tolerance in Southeast Asia were not detected, but the majority of the tested samples carried the pfmdr1 haplotype NFD and anti-malarial-associated mutations in the the pfcrt and pfdhfr genes. The first whole genome sequencing (WGS) was performed for Cape Verdean parasites that showed that the samples cluster together, have a very high level of similarity and are close to other parasites populations from West Africa.

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