Design of nucleotide-mimetic and non-nucleotide inhibitors of the translation initiation factor eIF4E: Synthesis, structural and functional characterisation.
Eukaryotic translation initiation factor 4E (eIF4E) is considered as the corner stone in the cap-dependent translation initiation machinery. Its role is to recruit mRNA to the ribosome through recognition of the 5'-terminal mRNA cap structure (m7GpppN, where G is guanosine, N is any nucleotide). eIF4E is implicated in cell transformation, tumourigenesis, and angiogenesis by facilitating translation of oncogenic mRNAs; it is thus regarded as an attractive anticancer drug target. We have used two approaches to design cap-binding inhibitors of eIF4E by modifying the N7-substituent of m7GMP and replacing the phosphate group with isosteres such as squaramides, sulfonamides, and tetrazoles, as well as by structure-based virtual screening aimed at identifying non-nucleotide cap-binding antagonists. Phosphomimetic nucleotide derivatives and highly ranking virtual hits were evaluated in a series of in vitro and cell-based assays to identify the first non-nucleotide eIF4E cap-binding inhibitor with activities in cell-based assays, N-[(5,6-dihydro-6-oxo-1,3-dioxolo[4,5-g]quinolin-7-yl)methyl]-N'-(2-methyl-propyl)-N-(phenyl-methyl)thiourea (14), including down-regulation of oncogenic proteins and suppression of RNA incorporation into polysomes. Although we did not observe cellular activity with any of our modified m7GMP phosphate isostere compounds, we obtained X-ray crystallography structures of three such compounds in complex with eIF4E, 5'-deoxy-5'-(1,2-dioxo-3-hydroxycyclobut-3-en-4-yl)amino-N7-methyl-guanosine (4a), N7-3-chlorobenzyl-5'-deoxy-5'-(1,2-dioxo-3-hydroxy-cyclobut-3-en-4-yl)amino-guanosine (4f), and N7-benzyl-5'-deoxy-5'-(trifluoromethyl-sulfamoyl)guanosine (7a). Collectively, the data we present on structure-based design of eIF4E cap-binding inhibitors should facilitate the optimisation of such compounds as potential anticancer agents.
School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Fadi
F
Soukarieh
Centre for Translational Chemical Biology, University of Edinburgh, Michael Swann Building, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK.
Matthew W
MW
Nowicki
M.R.C. Toxicology Unit, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
Amandine
A
Bastide
M.R.C. Toxicology Unit, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
Tuija
T
Pöyry
M.R.C. Toxicology Unit, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
Carolyn
C
Jones
M.R.C. Toxicology Unit, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
Kate
K
Dudek
School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Geetanjali
G
Patwardhan
School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
François
F
Meullenet
School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Neil J
NJ
Oldham
Centre for Translational Chemical Biology, University of Edinburgh, Michael Swann Building, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK.
Malcolm D
MD
Walkinshaw
M.R.C. Toxicology Unit, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
Anne E
AE
Willis
School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK. Electronic address: peter.fischer@nottingham.ac.uk.
Peter M
PM
Fischer
D000818:Animals; D040761:Biomimetic Materials / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D060326:Chemistry Techniques, Synthetic; D015195:Drug Design; D039561:Eukaryotic Initiation Factor-4E / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D009711:Nucleotides / Q000737:chemistry*; D011487:Protein Conformation; D012315:RNA Caps / Q000378:metabolism; D011817:Rabbits; D013890:Thiourea / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology
D039561:Eukaryotic Initiation Factor-4E; D009711:Nucleotides; D012315:RNA Caps; D013890:Thiourea
Cancer; Cap-binding inhibitor; Protein synthesis; eIF4E; mRNA translation