Importance of Post-translational Modifications in the Interaction of Proteins with Mineral Surfaces: The Case of Arginine Methylation and Silica surfaces

International audienceUnderstanding the mechanisms involved in the interaction of proteins with inorganic surfaces is of major interest for both basic research and practical applications involving nanotechnology. From the list of cellular proteins with the highest affinity for silica nanoparticles, we highlighted the group of proteins containing arginine–glycine–glycine (RGG) motifs. Biochemical experiments confirmed that RGG motifs interact strongly with the silica surfaces. The affinity of these motifs is further increased when the R residue is asymmetrically, but not symmetrically, dimethylated. Molecular dynamics simulations show that the asymmetrical dimethylation generates an electrostatic asymmetry in the guanidinium group of the R residue, orientating and stabilizing it on the silica surface. The RGG motifs (methylated or not) systematically target the siloxide groups on the silica surface through an ionic interaction, immediately strengthened by hydrogen bonds with proximal silanol and siloxane groups. Given that, in vivo, RGG motifs are often asymmetrically dimethylated by specific cellular methylases, our data add support to the idea that this type of methylation is a key mechanism for cells to regulate the interaction of the RGG proteins with their cellular partners

Consultation personnalisée d'évaluation du risque de cancer du sein: premiers résultats

International audienceIntroductionIn France, participation in the organized breast cancer screening program remains insufficient. A personalized approach adapted to the risk factors for breast cancer (RBC) should make screening more efficient. A RBC evaluation consultation would therefore make it possible to personalize this screening. Here we report our initial experience.Material and methodThis is a prospective study on women who were seen at the RBC evaluation consultation and analyzing: their profile, their risk assessed according to Tyrer Cuzick model (TC) ± Mammorisk© (MMR), the existence of an indication of oncogenetic consultation (Eisinger and Manchester score), their satisfaction and the recommended monitoring.ResultsAmong the women who had had a TCS and/or MMR evaluation of SCR (n = 153), 76 (50%) had a high risk (n = 67) or a very high risk (n = 9). Almost half (47%) had a possible (15%) or certain (32%) indication to an oncogenetic consultation. Regarding this consultation, 98% of women were satisfied or very satisfied. In total, 60% of women had a change in screening methods.ConclusionThis RBC evaluation consultation satisfies women and for a majority of them, modifies their methods of breast cancer screening.IntroductionL’adhésion en France au programme de dépistage organisé du cancer du sein demeure insuffisante. Une approche personnalisée adaptée aux facteurs de risque de cancer du sein (RCS) permettrait une meilleure efficience du dépistage. Une consultation d’évaluation du RCS permettrait donc de personnaliser ce dépistage. Nous rapportons ici notre expérience initiale.Matériel et méthodeIl s’agit d’une étude prospective portant sur les femmes ayant été vues à la consultation d’évaluation du RCS et analysant : leur profil, leur risque évalué selon les modèles de Tyrer Cuzick (TC) ± Mammorisk© (MMR), l’existence d’une indication de consultation d’oncogénétique (scores d’Eisinger et de Manchester), leur satisfaction et la surveillance préconisée.RésultatsParmi les femmes ayant eu une évaluation du RCS par le modèle TC et/ou MMR (n = 153), 76 (50 %) avaient un risque élevé (n = 67) ou très élevé (n = 9). Près de la moitié (47 %) avait une indication possible (15 %) ou certaine (32 %) à une consultation d’oncogénétique. Concernant cette consultation, 98 % des femmes étaient satisfaites ou très satisfaites. Au total, 60 % des femmes ont eu un changement des modalités de surveillance.ConclusionCette consultation d’évaluation du RCS satisfait les femmes et pour une majorité d’entre elles, modifie les modalités de leur surveillance mammaire

Post-transplant outcome of ovarian tissue cryopreserved after chemotherapy in hematological malignancies

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