1
|
Yamamura T, Narumi K, Ohata T, Satoh H, Mori T, Furugen A, Kobayashi M, Iseki K. Characterization of deoxyribonucleoside transport mediated by concentrative nucleoside transporters. Biochem Biophys Res Commun 2021; 558:120-125. [PMID: 33910126 DOI: 10.1016/j.bbrc.2021.04.075] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/18/2021] [Indexed: 12/28/2022]
Abstract
Human concentrative nucleoside transporters (CNTs) are responsible for cellular uptake of ribonucleosides; however, although it is important to better characterize CNT-subtype specificity to understand the systemic disposition of deoxyribonucleosides (dNs) and their analogs, the involvement of CNTs in transporting dNs is not fully understood. In this study, using COS-7 cells that transiently expressed CNT1, CNT2, or CNT3, we investigated if CNTs could transport not only ribonucleosides but also dNs, i.e., 2'-deoxyadenosine (dAdo), 2'-deoxyguanosine (dGuo), and 2'-deoxycytidine (dCyd). The cellular uptake study demonstrated that dAdo and dGuo were taken up by CNT2 but not by CNT1. Although dCyd was taken up by CNT1, no significant uptake was detected in COS-7 cells expressing CNT2. Similarly, these dNs were transported by CNT3. The apparent Km values of their uptake were as follows: CNT1, Km = 141 μM for dCyd; CNT2, Km = 62.4 μM and 54.9 μM for dAdo and dGuo, respectively; CNT3, Km = 14.7 μM and 34.4 μM for dGuo and dCyd, respectively. These results demonstrate that CNTs contribute not only to ribonucleoside transport but also to the transport of dNs. Moreover, our data indicated that CNT1 and CNT2 selectively transported pyrimidine and purine dNs, respectively, and CNT3 was shown to transport both pyrimidine and purine dNs.
Collapse
Affiliation(s)
- Taiki Yamamura
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharma Sciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Katsuya Narumi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharma Sciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan.
| | - Tsukika Ohata
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharma Sciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Hiroshi Satoh
- Research and Development division, Hokkaido Research Institute, Nissei Bio Co. Ltd, Eniwa, Hokkaido, Japan
| | - Takao Mori
- Research and Development division, Hokkaido Research Institute, Nissei Bio Co. Ltd, Eniwa, Hokkaido, Japan
| | - Ayako Furugen
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharma Sciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Masaki Kobayashi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharma Sciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan.
| | - Ken Iseki
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharma Sciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| |
Collapse
|
2
|
Vaskó B, Juhász V, Tóth B, Kurunczi A, Fekete Z, Krisjanis Zolnerciks J, Kis E, Magnan R, Bidon-Chanal Badia A, Pastor-Anglada M, Hazai E, Bikadi Z, Fülöp F, Krajcsi P. Inhibitor selectivity of CNTs and ENTs. Xenobiotica 2018; 49:840-851. [PMID: 30022699 DOI: 10.1080/00498254.2018.1501832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The concentrative nucleoside transporters (CNT; solute carrier family 28 (SLC28)) and the equilibrative nucleoside transporters (ENT; solute carrier family 29 (SLC29)) are important therapeutic targets but may also mediate toxicity or adverse events. To explore the relative role of the base and the monosaccharide moiety in inhibitor selectivity we selected compounds that either harbor an arabinose moiety or a cytosine moiety, as these groups had several commercially available drug members. The screening data showed that more compounds harboring a cytosine moiety displayed potent interactions with the CNTs than compounds harboring the arabinose moiety. In contrast, ENTs showed a preference for compounds with an arabinose moiety. The correlation between CNT1 and CNT3 was good as five of six compounds displayed IC50 values within the threefold threshold and one displayed a borderline 4-fold difference. For CNT1 and CNT2 as well as for CNT2 and CNT3 only two of six IC50 values correlated and one displayed a borderline 4-fold difference. Interestingly, of the six compounds that potently interacted with both ENT1 and ENT2 only nelarabine displayed selectivity. Our data show differences between inhibitor selectivities of CNTs and ENTs as well as differences within the CNT family members.
Collapse
Affiliation(s)
| | | | - Beáta Tóth
- b SOLVO Biotechnology , Budaörs , Hungary
| | | | | | | | - Emese Kis
- a SOLVO Biotechnology , Szeged , Hungary
| | | | - Axel Bidon-Chanal Badia
- c Departament de Nutrició, Ciències de l'Alimentació i Gastronomia, Facultat de Farmàcia i Ciències de l'Alimentació and Institute of Biomedicine (IBUB), Campus de l'Alimentació de Torribera , Universitat de Barcelona , Santa Coloma de Gramenet , Spain
| | - Marçal Pastor-Anglada
- d Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia and Institute of Biomedicine (IBUB) , Universitat de Barcelona , Barcelona , Spain.,e Oncology Program , National Biomedical Research Institute on Liver and Gastrointestinal Diseases (CIBER EHD), Instituto de Salud Carlos III , Madrid , Spain
| | | | | | - Ferenc Fülöp
- g Institute of Pharmaceutical Chemistry, University of Szeged , Szeged , Hungary
| | - Peter Krajcsi
- a SOLVO Biotechnology , Szeged , Hungary.,h Department of Morphology and Physiology, Faculty of Health Sciences , Semmelweis University , Budapest , Hungary.,i Faculty of Information Technology and Bionics , Pázmány Péter Catholic University , Budapest , Hungary
| |
Collapse
|
3
|
Kumar Deokar H, Barch HP, Buolamwini JK. Homology Modeling of Human Concentrative Nucleoside Transporters (hCNTs) and Validation by Virtual Screening and Experimental Testing to Identify Novel hCNT1 Inhibitors. ACTA ACUST UNITED AC 2017; 6. [PMID: 29167753 DOI: 10.4172/2169-0138.1000146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Objective The nucleoside transporter family is an emerging target for cancer, viral and cardiovascular diseases. Due to the difficulty in the expression, isolation and crystallization of membrane proteins, there is a lack of structural information on any of the mammalian and for that matter the human proteins. Thus the objective of this study was to build homology models for the three cloned concentrative nucleoside transporters hCNT1, hCNT2 and hCNT3 and validate them for screening towards the discovery of much needed inhibitors and probes. Methods The recently reported crystal structure of the Vibrio cholerae concentrative nucleoside transporter (vcCNT), has satisfactory similarity to the human CNT orthologues and was thus used as a template to build homology models of all three hCNTs. The Schrödinger modeling suite was used for the exercise. External validation of the homology models was carried out by docking a set of recently reported known hCNT1 nucleoside class inhibitors at the putative binding site using induced fit docking (IDF) methodology with the Glide docking program. Then, the hCNT1 homology model was subsequently used to conduct a virtual screening of a 360,000 compound library, and 172 compounds were obtained and biologically evaluated for hCNT 1, 2 and 3 inhibitory potency and selectivity. Results Good quality homology models were obtained for all three hCNTs as indicated by interrogation for various structural parameters and also external validated by docking of known inhibitors. The IDF docking results showed good correlations between IDF scores and inhibitory activities; particularly for hCNT1. From the top 0.1% of compounds ranked by virtual screening with the hCNT1 homology model, 172 compounds selected and tested for against hCNT1, hCNT2 and hCNT3, yielded 14 new inhibitors (hits) of (i.e., 8% success rate). The most active compound exhibited an IC50 of 9.05 μM, which shows a greater than 25-fold higher potency than phlorizin the standard CNT inhibitor (IC50 of 250 μM). Conclusion We successfully undertook homology modeling and validation for all human concentrative nucleoside transporters (hCNT 1, 2 and 3). The proof-of-concept that these models are promising for virtual screening to identify potent and selective inhibitors was also obtained using the hCNT1 model. Thus we identified a novel potent hCNT1 inhibitor that is more potent and more selective than the standard inhibitor phlorizin. The other hCNT1 hits also mostly exhibited selectivity. These homology models should be useful for virtual screening to identify novel hCNT inhibitors, as well as for optimization of hCNT inhibitors.
Collapse
Affiliation(s)
- Hemant Kumar Deokar
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 847 Monroe Avenue, Suite 327, Memphis, Tennessee, 38163, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, 60064, USA
| | - Hilaire Playa Barch
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 847 Monroe Avenue, Suite 327, Memphis, Tennessee, 38163, USA
| | - John K Buolamwini
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 847 Monroe Avenue, Suite 327, Memphis, Tennessee, 38163, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, 60064, USA
| |
Collapse
|
4
|
Abstract
Secondary active transporters are responsible for the cellular uptake of many biologically important molecules, including neurotransmitters, nutrients, and drugs. Because of their physiological and clinical importance, a method for assessing their transport activity in vitro is necessary to gain a better understanding of how these transporters function at the molecular level. In this chapter, we describe a protocol for reconstituting the concentrative nucleoside transporter from Vibrio cholerae into proteoliposomes. We then describe a radiolabeled substrate uptake assay that can be used to functionally characterize the transporter. These methods are relatively common and can be applied to other secondary active transporters, with or without some modification.
Collapse
Affiliation(s)
- Zachary Lee Johnson
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA
| | - Seok-Yong Lee
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA.
| |
Collapse
|