title: Cycloalkyl-substituted aryl chloroethylureas inhibiting cell cycle progression in G0/G1 phase and thioredoxin-1 nuclear translocation.
abstract: 1-(2-Chloroethyl)-3-(4-cyclohexylphenyl)urea (cHCEU) has been shown to abrogate the presence of thioredoxin-1 into the nucleus through its selective covalent alkylation. In the present letter we have evaluated the structure-activity relationships of the substituents at positions 3 and 4 of the phenyl ring of cHCEU derivatives on cell cycle progression and thioredoxin-1 nuclear translocation. Active CEU derivatives exhibited GI(50) ranging from 1.9 to 49muM on breast carcinoma MCF-7, skin melanoma M21, and colon carcinoma HT-29 cells. On one hand, compounds 1, 2, 9c, 10c, 13, and 14 arrested the cell cycle in G(2)/M phase while CEUs 3, 4, 5c, 6c, 11c, and 12c blocked the cell division in G(0)/G(1) phase. On the other hand, CEUs 2-4, 5c, 7c, 8c, 11c, and 12c abrogated the translocation of thioredoxin-1 while the other CEU derivatives were inactive in that respect. Our results suggest that CEU substituted on the phenyl ring at position 3 or 4 by lower cycloalkyl or cycloalkoxy groups arrest cell progression in G(0)/G(1) phase through mechanism of action different from their antimicrotubule counterparts, presumably via thioredoxin-1 alkylation and modulation of its activity. The mechanism of action of these new molecules is still undetermined. However, the significant accumulation of cells in G(0)/G(1) phase suggests that these molecules may act similarly to known chemopreventive agents against cancers. In addition, the inhibition of Trx-1 nuclear localization also suggests the abrogation of an important chemoresistance mechanism towards a variety of chemotherapeutic agents.
authors.affiliation: Unité des Biotechnologies et de Bioingénierie, CRCHUQ, Hôpital Saint-François d'Assise, Québec, QC, Canada. jessica.fortin.1@ulaval.ca
authors.forename: Jessica S
authors.initials: JS
authors.lastname: Fortin
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Côté
authors.forename: Jacques
authors.initials: J
authors.lastname: Lacroix
authors.forename: Alexandre
authors.initials: A
authors.lastname: Patenaude
authors.forename: Eric
authors.initials: E
authors.lastname: Petitclerc
authors.forename: René
authors.initials: R
authors.lastname: C-Gaudreault
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D016193:G1 Phase / Q000187:drug effects*; D006801:Humans; D015394:Molecular Structure; D016192:Resting Phase, Cell Cycle / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects; D013237:Stereoisomerism; D013879:Thioredoxins / Q000378:metabolism*; D014508:Urea / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*
chemical_list: C491203:TXN protein, human; D013879:Thioredoxins; D014508:Urea