Quick and Simple Detection Technique to Assess the Binding of Antimicrotubule Agents to the Colchicine-Binding Site

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

Involvement of TLR2 in Recognition of Acute Gammaherpesvirus-68 Infection

Toll-like receptors (TLRs) play a crucial role in the activation of innate immunity in response to many viruses. We previously reported the implication of TLR2 in the recognition of Epstein-Barr virus (EBV) by human monocytes. Because murine gammaherpesvirus-68 (MHV-68) is a useful model to study human gammaherpesvirus pathogenesis in vivo, we evaluated the importance of mouse TLR2 in the recognition of MHV-68.In studies using transfected HEK293 cells, MHV-68 lead to the activation of NF-κB reporter through TLR2. In addition, production of interleukin-6 (IL-6) and interferon-α (IFN-α) upon MHV-68 stimulation was reduced in murine embryonic fibroblasts (MEFs) derived from TLR2-/- and MyD88-/- mice as compared to their wild type (WT) counterpart. In transgenic mice expressing a luciferase reporter gene under the control of the mTLR2 promoter, MHV-68 challenge activated TLR2 transcription. Increased expression levels of TLR2 on blood granulocytes (CD115(-)Gr1(+)) and inflammatory monocytes (CD115(+)Gr1(+)), which mobilized to the lungs upon infection with MHV-68, was also confirmed by flow cytometry. Finally, TLR2 or MyD88 deficiency was associated with decreased IL-6 and type 1 IFN production as well as increased viral burden during short-term challenges with MHV-68.TLR2 contributes to the production of inflammatory cytokines and type 1 IFN as well as to the control of viral burden during infection with MHV-68. Taken together, our results suggest that the TLR2 pathway has a relevant role in the recognition of this virus and in the subsequent activation of the innate immune response

Pourquoi les étudiants sont-ils moins motivés après leur première session qu’à leur arrivée au cégep?

Cette communication s’inscrit dans le cadre de l’Enquête sur la réussite à l’enseignement collégial menée par ÉCOBES, le CRISPESH et l’IRIPII en collaboration avec la Fédération des cégeps et financée par le ministère de l’Enseignement supérieur."À l’arrivée au cégep, la grande majorité des étudiantes et des étudiants se disent très motivés à réussir leurs études, mais lorsqu’on leur repose la question après une session, près de la moitié d’entre eux indiquent que leur motivation a diminué.Pourquoi leur motivation a-t-elle chuté? Est-ce que certains groupes sont plus à risque de présenter une telle baisse? À l’inverse, qu’est-ce qui fait en sorte que plusieurs sont encore plus motivés qu’à leur arrivée? Des analyses permettent de mieux comprendre les facteurs et les trajectoires de motivation au cours de la première année d’études collégiales. Des pistes seront proposées pour favoriser la motivation, et des échanges avec l’assistance seront au cœur des réflexions." -- AQP

La réussite en première session, encore d’actualité en 2024?

"Il y a 10 ans, le SRAM démontrait que le fait d’échouer à au moins un cours à sa première session diminuait de moitié ses chances d’obtenir un diplôme. De plus, une personne étudiante ayant une MGS faible réussissant tous ses cours avait les mêmes chances d'avoir un diplôme qu’une personne avec une MGS élevée qui échouait à au moins un cours.Ces constats sont-ils toujours vrais? Quelles caractéristiques à l’entrée au cégep sont associées à une plus faible réussite à la première session? Certaines sous-populations étudiantes risquent-elles plus l’échec? Les facteurs de risque qui prévalaient avant la pandémie sont-ils encore les mêmes? Des pistes seront proposées par l’équipe de recherche à partir des analyses de la deuxième phase de l’Enquête sur la réussite à l’enseignement collégial pour favoriser la réussite et les échanges avec les personnes participant à l’atelier, tout en enrichissant les réflexions issues du projet." -- AQP

Rendez-vous du MES : enquête SPEC sur la réussite au collégial. Partie 03 : les étudiant.es de 24 ans et plus et les ÉPGC

Rendez-vous du MES : Enquête SPEC sur la réussite au collégial : Quatre centres collégiaux de transfert : ÉCOBES, IRIPI, CRISPESH et JACOBBProjet financé par le ministère de l’Enseignement supérieur dans le cadre du Chantier sur la réussite au collégialMené conjointement par ÉCOBES, le CRISPESH et l’IRIPI en collaboration avec la Fédération des cégep

Optimized N-phenyl-N'-(2-chloroethyl)ureas as potential antineoplastic agents: synthesis and growth inhibition activity

In our ongoing research program aimed at the optimization of microtubule-self-assembly disrupting agents, we have prepared three series of phenylurea analogues (CEU), derived from N-(3-ω-hydroxyalkyl or 4-ω-hydroxyalkyl or 3-ω-hydroxyalkynyl)-phenyl-N′-(2-chloroethyl)ureas. Most compounds exhibit potent growth inhibitory activity on human colon carcinoma HT-29, human skin melanoma M21, and human breast carcinoma MCF-7 tumor cell lines, with a GI50 ranging from 250 nM to 8 μM. Among these new molecules, three CEUs exhibit GI50 in the nanomolar range. They are more potent by approximately an order of magnitude than previously described CEU analogues. As such, they are attractive hit compounds for the development of potent new alkylating antitubulin drugs

Optimized N-phenyl-N′-(2-chloroethyl)ureas as potential antineoplastic agents: Synthesis and growth inhibition activity

International audienceIn our ongoing research program aimed at the optimization of microtubule-self-assembly disrupting agents, we have prepared three series of phenylurea analogues (CEU), derived from N-(3-omega-hydroxyalkyl or 4-omega-hydroxyalkyl or 3-omega-hydroxyalkynyl)-phenyl-N'-(2-chloroethyl)ureas. Most compounds exhibit potent growth inhibitory activity on human colon carcinoma HT-29, human skin melanoma M21, and human breast carcinoma MCF-7 tumor cell lines, with a GI50 ranging from 250 nM to 8 microM. Among these new molecules, three CEUs exhibit GI50 in the nanomolar range. They are more potent by approximately an order of magnitude than previously described CEU analogues. As such, they are attractive hit compounds for the development of potent new alkylating antitubulin drugs

Synthesis, antiproliferative activity evaluation and structure-activity relationships of novel aromatic urea and amide analogues of N-phenyl-N’-(2-chloroethyl)ureas

Seven subsets of aromatic urea and amide analogues of N-phenyl-N0-(2-chloroethyl)ureas (CEU) have been synthesized by nucleophilic addition of 3-chloropropylisocyanate, 2-chloroacetylisocyanate, ethylisocyanate, 2-chloroacetyl chloride, 3-chloropropanoyl chloride, 4-chlorobutanoyl chloride, and acryloyl chloride, espectively, to selected anilines or benzylamines to afford 3-chloropropylureas (1, CPU), 2-chloroacetylureas (2, CAU), ethylureas (3, EU), 2-hloroacetamides (4, CA), 3-chloropropionamides (5, CPA), 4-chlorobutyramides (6, CBA) and acrylamides (7, cr). The molecular structure of these compounds has been confirmed by IR, 1H and 13C NMR, and MS spectra and their purity also confirmed by HPLC. The CEU analogues were evaluated for their antiproliferative activity against three human tumor cell lines, namely human colon carcinoma HT-29, human skin melanoma M21, and human breast carcinoma MCF-7. CAU (2c to 2g), CA (4a to 4d, 4f and 4g), CPA (5a) and Acr (7a and 7b) had IC50 ranging from 1.4 to 25 mM. CAU, CA, CPA and Acr exhibited interesting antiproliferative activity through mechanism(s) of action unrelated to the acylation of glutamic acid at position 198 on b-tubulin that is characterizing CEU