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Fortin, Sébastien

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Fortin

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Sébastien

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Université Laval. Faculté de pharmacie

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ncf13678332

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  • PublicationAccès libre
    A comparative molecular field and comparative molecular similarity indices analyses (CoMFA and CoMSIA) of N-phenyl-N'-(2-chloroethyl)urea targeting the colchicine-binding site as anticancer agents
    (Pergamon, 2007-11-05) Fortin, Sébastien; Labrie, Philippe; C. Gaudreault, René.; Wei, Lianhu; Moreau, Emmanuel; Kotra, Lakshmi P.
    To decipher the mechanism underlying the covalent binding of N-phenyl-N′-(2-chloroethyl)ureas (CEU) to the colchicine-binding site on βII-tubulin and to design new and selective antimitotic drugs, we developed 3D quantitative structure–activity relationships (3D-QSAR) models using CoMFA and CoMSIA analyses. The present study correlates the cell growth inhibition activities of 56 structurally related CEU derivatives to several physicochemical parameters representing steric, electrostatic, and hydrophobic fields. Both CoMFA and CoMSIA models using two different optimum numbers of components (ONC) 10 and 4, respectively, gave good internal predictions and their cross-validated r2 values were between 0.639 and 0.743. These comprehensive CoMFA and CoMSIA models are useful in understanding the structure–activity relationships of CEU. The two models were compared to the X-ray crystal structure of the complex of tubulin–colchicine and analyzed for similarities between the two modes of analysis. These models will inspire the design of new CEU derivatives with enhanced inhibition of tumor cell growth and targeting specificity of βII-tubulin and the cytoskeleton.
  • PublicationAccès libre
    Evaluation of the time-dependent antiproliferative activity and liver microsome stability of 3 phenyl 4-(2-oxo-3-alkylimidazolidin-1-yl)benzenesulfonates as promising CYP1A1-dependent antimicrotubule prodrugs
    (Pharmaceutical Press, 2019-11-14) Zarifi Khosroshahi, Mitra; Fortin, Sébastien; Gobeil, Stéphane; Gaudreault, René C.; Gagné-Boulet, Mathieu; Chavez Alvarez, Atziri Corin
    Objectives In this study, the antiproliferative activity of 3 phenyl 4-(2-oxo-3-alkylimidazolidin-1-yl)benzenesulfonates (PAIB-SOs) was assessed in a time-dependent manner together with their hepatic stability and metabolism using human, mouse and rat liver microsomes. Methods CEU-818, -820 and -913 were selected as promising hit compounds. Their antiproliferative activity on human breast carcinoma MCF-7 cells was evaluated using escalating concentrations of drugs at 24, 36 and 48 h and the sulforhodamine B assay. Their hepatic stability was evaluated by HPLC-UV of extracts obtained from human, mouse and rat liver microsomes. Key findings The antiproliferative activity of PAIB-SOs is concentration and time-dependent and requires between 24 and 36 h of contact with MCF-7 cells to detect a significant antiproliferative activity. PAIB-SOs stability in microsomes usually decreases following this order: human ≈ (rat > mouse). The CEU-913 exhibits the longest half-life in rat and human liver microsomes while the CEU-820 exhibits the longest half-life in mouse liver microsomes. Conclusions Our in vitro results suggest that PAIB-SOs should have a minimum contact time of 24 h with the tumour to trigger significant antitumoural activity. The activity of mouse liver microsomes towards PAIB-SOs is higher than rat microsomes and tends to be higher than human liver microsomes.
  • PublicationAccès libre
    Quick and simple detection technique to assess the binding of antimicrotubule agents to the colchicine-binding site
    (Springer Nature, 2010-04-08) Fortin, Sébastien; Côté, Marie-France; Petitclerc, Éric; Lacroix, Jacques M.; C. Gaudreault, René.; Moreau, Emmanuel
    Development of antimitotic binding to the colchicine-binding site for the treatment of cancer is rapidly expanding. Numerous antimicrotubule agents are prepared every year, and the determination of their binding affinity to tubulin requires the use of purified tubulins and radiolabeled ligands. Such a procedure is costly and time-consuming and therefore is limited to the most promising candidates. Here, we report a quick and inexpensive method that requires only usual laboratory resources to assess the binding of antimicrotubules to colchicine-binding site. The method is based on the ability of N,N'-ethylene-bis(iodoacetamide) (EBI) to crosslink in living cells the cysteine residues at position 239 and 354 of β-tubulin, residues which are involved in the colchicine-binding site. The β-tubulin adduct formed by EBI is easily detectable by Western blot as a second immunoreacting band of β-tubulin that migrates faster than β-tubulin. The occupancy of colchicine-binding site by pertinent antimitotics inhibits the formation of the EBI: β-tubulin adduct, resulting in an assay that allows the screening of new molecules targeting this binding site.
  • PublicationAccès libre
    Substituted phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonamides as antimitotics. Antiproliferative, antiangiogenic and antitumoral activity, and quantitative structure-activity relationships
    (2011-08-30) Fortin, Sébastien; Wei, Lianhu; Côté, Marie-France; Petitclerc, Éric; Lacroix, Jacques M.; C. Gaudreault, René.; Moreau, Emmanuel; Kotra, Lakshmi P.
    The importance of the bridge linking the two phenyl moieties of substituted phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonates (PIB-SOs) was assessed using a sulfonamide group, which is a bioisostere of sulfonate and ethenyl groups. Forty one phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonamide (PIB-SA) derivatives were prepared and biologically evaluated. PIB-SAs exhibit antiproliferative activities at the nanomolar level against sixteen cancer cell lines, block the cell cycle progression in G2/M phase, leading to cytoskeleton disruption and anoikis. These results were subjected to CoMFA and CoMSIA analyses to establish quantitative structure-activity relationships. These results evidence that the sulfonate and sulfonamide moieties are reciprocal bioisosteres and that phenylimidazolidin-2-one could mimic the trimethoxyphenyl moiety found in the structure of numerous potent antimicrotubule agents. Finally, compounds 16 and 17 exhibited potent antitumor and antiangiogenic activities on HT-1080 fibrosarcoma cells grafted onto chick chorioallantoic membrane similar to CA-4 without significant toxicity for the chick embryos, making this class of compounds a promising class of anticancer agents.
  • PublicationAccès libre
    N-Phenyl-N’-(2-chloroethyl)ureas (CEUs) as potential antineoplastic agents. part 3 : role of carbonyl group
    (Oxford Pergamon, 2007-10-27) Fortin, Sébastien; Rousseau, Jean; Lacroix, Jacques M.; C. Gaudreault, René.; Patenaude, Alexandre.; Moreau, Emmanuel
    n the course of the development of N-phenyl-N′-(2-chloroethyl)ureas (CEUs) as potential antineoplastic agents, we investigated the effect of carbonylated substituting chains of the aromatic ring of CEU on their covalent binding to the colchicine-binding site (C-BS). In this study, we found that CEU, 5e, 5f, 8e, and 8f substituted by either a methyl ester or a methyl ketyl group at the ω-position exhibited a significant antiproliferative activity on HT-29, M21, and MCF-7 tumor cells. SDS–PAGE assays and cell cycle analysis confirmed that 5e, 5f, 8e, and 8f covalently bind to the C-BS and arrest the cell division in G2/M phase. Surprisingly, the presence of ω-carboxyl, ω-ethyl esters or ω-amides decreased significantly both the antiproliferative activity and the specificity toward β-tubulin.
  • PublicationAccès libre
    Phenyl 4-(2-oxopyrrolidin-1-yl)benzenesulfonates and phenyl 4-(2-oxopyrrolidin-1-yl)benzenesulfonamides as new antimicrotubule agents targeting the colchicine-binding site
    (Elsevier, 2021-03-05) Fortin, Sébastien; Bouzriba, Chahrazed; Gagné-Boulet, Mathieu; Chavez Alvarez, Atziri Corin
    We recently designed and prepared new families of potent antimicrotubule agents designated as N-phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonates (PIB–SOs) and phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonamides (PIB–SAs). Our previous structure-activity relationship studies (SAR) focused on the aromatic ring B of PIB-SOs and PIB-SAs leaving the impact of the phenylimidazolidin-2-one moiety (ring A) on the binding to the colchicine-binding site (C-BS) poorly studied. Therefore, the aim of the present study was to evaluate the effect of replacing the imidazolidin-2-one (IMZ) group by a pyrrolidin-2-one moiety. To that end, 15 new phenyl 4-(2-oxopyrrolidin-1-yl)benzenesulfonate (PYB–SO) and 15 phenyl 4-(2-oxopyrrolidin-1-yl)benzenesulfonamide (PYB-SA) derivatives were designed, prepared, chemically characterised and biologically evaluated. PYB-SOs and PYB-SAs exhibit antiproliferative activity in the low nanomolar to low micromolar range (0.0087–8.6 μM and 0.056–21 μM, respectively) on human HT-1080, HT-29, M21 and MCF7 cancer cell lines. Moreover, they block cell cycle progression in G2/M phase. Immunofluorescence, tubulin affinity and tubulin polymerisation assays show that they cause microtubule depolymerisation by docking the C-BS. In addition, docking assays with the most potent derivatives show binding affinity toward the C-BS and they also exhibit weak or no toxicity toward chick embryos. Finally, physicochemical properties calculated using the SwissADME algorithm show that PYB-SOs and PYB-SAs are promising new families of antimicrotubule agents.
  • PublicationRestreint
    Characterization of the covalent binding of N-phenyl-N'-(2-chloroethyl)ureas to β-tubulin : importance of glutamic acid 198 in microtubule stability
    (American Society for Pharmacology and Experimental Therapeutics, 2011-01-18) Fortin, Sébastien; Bouchon, Bernadette; Lacroix, Jacques M.; Chambon, Christophe; C. Gaudreault, René.; Moreau, Emmanuel; Chezal, Jean-Michel; Degoul, Françoise
    N-Phenyl-N′-(2-chloroethyl)ureas (CEUs) are antimicrotubule agents interacting covalently with β-tubulin near the colchicine-binding site (C-BS). Glutamyl 198 residue in β-tubulin (Glu198), which is adjacent to the C-BS behind the two potent nucleophilic residues, Cys239 and Cys354, has been shown to covalently react with 1-(2-chloroethyl)-3-(4-iodophenyl)urea (ICEU). By use of mass spectrometry, we have now identified residues in β-tubulin that have become modified irreversibly by 1-(2-chloroethyl)-3-[3-(5-hydroxypentyl)phenyl]urea (HPCEU), 1-[4-(3-hydroxy-4-methoxystyryl)phenyl]-3-(2-chloroethyl)urea (4ZCombCEU), and N,N′-ethylenebis(iodoacetamide) (EBI). The binding of HPCEU and 4ZCombCEU to β-tubulin resulted in the acylation of Glu198, a protein modification of uncommon occurrence in living cells. Prototypical CEUs then were used as molecular probes to assess, in mouse B16F0 and human MDA-MB-231 cells, the role of Glu198 in microtubule stability. For that purpose, we studied the effect of Glu198 modification by ICEU, HPCEU, and 4ZCombCEU on the acetylation of Lys40 on α-tubulin, a key indicator of microtubule stability. We show that modification of Glu198 by prototypical CEUs correlates with a decrease in Lys40 acetylation, as observed also with other microtubule depolymerizing agents. Therefore, CEU affects the stability and the dynamics of microtubule, likewise a E198G mutation, which is unusual for xenobiotics. We demonstrate for the first time that EBI forms an intramolecular cross-link between Cys239 and Cys354 of β-tubulin in living cells. This work establishes a novel basis for the development of future chemotherapeutic agents and provides a framework for the design of molecules useful for studying the role of Asp and Glu residues in the structure/function and the biological activity of several cellular proteins under physiological conditions.
  • PublicationAccès libre
    Mechanism of action of N-phenyl-N'-(2-chloroethyl)ureas in the colchicine-binding site at the interface between a- and b-tubulin
    (Pergamon, 2009-04-01) Fortin, Sébastien; Wei, Lianhu; Labrie, Philippe; Petitclerc, Éric; C. Gaudreault, René.; Moreau, Emmanuel; Kotra, Lakshmi P.
    Computational tools such as CoMSIA and CoMFA models reported in a recent study revealed the structure–activity relationships ruling the interactions occurring between hydrophobic N-phenyl-N′-(2-chloroethyl)ureas (CEU) and the colchicine-binding site (C-BS) on βΙΙ-tubulin. Here, we describe the mechanisms involved in the covalent binding of three subsets of CEU derivatives to the C-BS. The FlexiDock experiments confirmed that the interaction of non-covalent portions of the CEU auxophore moiety of CEU is involved in the binding of the drug to the C-BS facilitate the nucleophilic attack of Glu-β198 rather than Cys-β239. In addition, these studies suggest that Cys-β239 together with Asn-α99, Ser-α176, Thr-α177, Leu-β246, Asn-β247, Ala-β248, Lys-β252 and Asn-β256 are implicated in the stabilization of a C-BS–CEU complex prior to the acylation of Glu-β198 by CEU. Our molecular models propose the formation of a stabilized C-BS–CEU complex before the completion of the Glu-β198 acylation; acylation triggering conformational changes of β-tubulin, microtubule depolymerization and anoikis. The computational models presented here might be useful to the design of selective and more potent C-BS inhibitors. Of interest, in vivo acylation of acidic amino acid residues by xenobiotics is an unusual reaction and may open new approaches for the design of irreversible protein inhibitors such as tubulin.
  • PublicationAccès libre
    Inhibitory effects of cytoskeleton disrupting drugs and GDP-locked Rab mutants on bradykinin B2 receptor cycling
    (Academic Press, 2013-05-01) Fortin, Sébastien; Roy, Caroline; Marceau, François; Lodge, Robert; Gera, Lajos; C. Gaudreault, René.; Charest-Morin, Xavier
    The bradykinin (BK) B2 receptor (B2R) is G protein coupled and phosphorylated upon agonist stimulation; its endocytosis and recycling are documented. We assessed the effect of drugs that affect the cytoskeleton on B2R cycling. These drugs were targeted to tubulin (paclitaxel, or the novel combretastatin A-4 mimetic 3,4,5-trimethoxyphenyl-4-(2-oxoimidazolidin-1-yl)benzenesulfonate [IMZ-602]) and actin (cytochalasin D). Tubulin ligands did not alter agonist-induced receptor endocytosis, as shown using antibodies reactive with myc-tagged B2Rs (microscopy, cytofluorometry), but rather reduced the progression of the ligand–receptor–β-arrestin complex from the cell periphery to the interior. The 3 fluorescent probes of this complex (B2R-green fluorescent protein [B2R-GFP], the fluorescent agonist fluorescein-5-thiocarbamoyl-D-Arg-[Hyp3, Igl5, Oic7, Igl8]-BK and β-arrestin2–GFP) were condensed in punctuate structures that remained close to the cell surface in the presence of IMZ-602. Cytochalasin D selectively inhibited the recycling of endocytosed B2R-GFP (B2R-GFP imaging, [3H]BK binding). Dominant negative (GDP-locked)-Rab5 and -Rab11 reproduced the effects of inhibitors of tubulin and actin, respectively, on the cycling of B2R-GFP. GDP-locked-Rab4 also inhibited B2R-GFP recycling to the cell surface. Consistent with the displacement of cargo along specific cytoskeletal elements, Rab5-associated progression of the endocytosed BK B2R follows microtubules toward their (−) end, while its recycling progresses along actin fibers to the cell surface. However, tubulin ligands do not suppress the tested desensitization or resensitization mechanisms of the B2R
  • PublicationAccès libre
    Synthesis, biological evaluation and structure-activity relationships of novel substituted N-phenyl ureidobenzenesulfonate derivatives blocking cell cycle progression in S-phase and inducing DNA double-strand breaks
    (American Chemical Society, 2012-07-13) Fortin, Sébastien; Masson, Jean-Yves; Vevey, Florence; Turcotte, Vanessa; Côté, Marie-France; Lacroix, Jacques M.; Coulombe, Yan.; C. Gaudreault, René.
    Twenty-eight new substituted N-phenyl ureidobenzenesulfonate (PUB-SO) and 18 N-phenylureidobenzenesulfonamide (PUB-SA) derivatives were prepared. Several PUB-SOs exhibited antiproliferative activity at the micromolar level against the HT-29, M21, and MCF-7 cell lines and blocked cell cycle progression in S-phase similarly to cisplatin. In addition, PUB-SOs induced histone H2AX (γH2AX) phosphorylation, indicating that these molecules induce DNA double-strand breaks. In contrast, PUB-SAs were less active than PUB-SOs and did not block cell cycle progression in S-phase. Finally, PUB-SOs 4 and 46 exhibited potent antitumor activity in HT-1080 fibrosarcoma cells grafted onto chick chorioallantoic membranes, which was similar to cisplatin and combretastatin A-4 and without significant toxicity toward chick embryos. These new compounds are members of a promising new class of anticancer agents.