Characterization of new, efficient Mycobacterium tuberculosis topoisomerase-I inhibitors and their interaction with human ABC multidrug transporters

Abstract

Drug resistant tuberculosis (TB) is a major worldwide health problem. In addition to the bacterial mechanisms, human drug transporters limiting the cellular accumulation and the pharmacological disposition of drugs also influence the efficacy of treatment. Mycobacterium tuberculosis topoisomerase-I (MtTopo-I) is a promising target for antimicrobial treatment. In our previous work we have identified several hit compounds targeting the MtTopo-I by in silico docking. Here we expand the scope of the compounds around three scaffolds associated with potent MtTopo-I inhibition. In addition to measuring the effect of newly generated compounds on MtTopo-I activity, we characterized the compounds’ antimicrobial activity, toxicity in human cells, and interactions with human multidrug transporters. Some of the newly developed MtTopo-I inhibitors have strong antimicrobial activity and do not harm mammalian cells. Moreover, our studies revealed significant human ABC drug transporter interactions for several MtTopo-I compounds that may modify their ADME-Tox parameters and cellular effects. Promising new drug candidates may be selected based on these studies for further anti-TB drug development.

Identification of anticancer OATP2B1 substrates by an in vitro triple-fluorescence-based cytotoxicity screen

“…In this study, we characterize Mes-Sa (human sarcoma) and A431 (human epidermoid carcinoma) cells, along with their transporter-expressing derivatives. In prior work our group has shown that both cell lines are suitable for the identification of cytotoxic MDR-substrates and MDR-selective compounds (Elkind et al 2005; Hegedűs et al 2009; Türk et al 2009; Nerada et al 2016; Füredi et al 2017; Szabó et al 2018; Temesszentandrási-Ambrus et al 2018). To evaluate the influence of OATP2B1 in the context of the MDR exporters, we wanted to use the same in vitro model.…”

Type IA Topoisomerases as Targets for Infectious Disease Treatments

“…In silico virtual screening employing docking and molecular dynamics (MD) simulations can be used first to identify potential inhibitors from compound libraries, followed by biochemical assays on a small number of in silico hits with the highest predicted binding affinity to confirm the interaction and assess the topoisomerase inhibition and antimicrobial activity. This approach has been applied to identify inhibitors for E. coli and M. tuberculosis topoisomerase I using either crystal structures or target structures generated by computational modeling [ 94 , 95 , 96 , 97 , 98 ].…”

“…The 639 compounds with MIC values < 6 μM were assayed for inhibition of M. tuberculosis topoisomerase I activity, and the results on the 108 compounds found to be active at 100 μM were used for building machine learning models for M. tuberculosis topoisomerase I inhibitors [ 97 ]. A selected set of seven Vichem NCL molecules with benzo(g)-quinoxaline, quinoxaline, or styryl-benzo(g)-quinazoline scaffolds was further characterized [ 98 ]. Cytotoxicity was measured against three human cell lines.…”

“…Cytotoxicity was measured against three human cell lines. In silico docking predicted strong binding affinity to specific sites on M. tuberculosis topoisomerase I through interactions with R167 and R114 [ 97 , 98 ]. The interaction of the selected hits with the human ATP-binding cassette (ABC) multi-drug transporters was assessed for potential drug resistance.…”

“…The interaction of the selected hits with the human ATP-binding cassette (ABC) multi-drug transporters was assessed for potential drug resistance. The human ABCB (MDR/TAP) transporter family plays a major role in multiple drug resistance (MDR) against a variety of tuberculosis therapies, such as fluoroquinolones and aminoglycosides [ 98 ]. Most of the hits demonstrated considerable interaction with the transporters, except for VCC891909 ( Figure 7 ).…”