Peptide-assisted cancer cell migration along engineered surfaces

Cell migration is a key process in human biology and the understanding of its complex mechanisms has a crucial importance in biomaterials,[1] engineering, medicine,[2] cell biology and immunology. This important feature is predominant in biochemical processes such as tissue regeneration, cancer metastasis and embryogenesis. Cells can detect chemical and physical gradients both on surface and in solution and respond to them with oriented movement therefore controlling such processes could potentially result in major advances in cancer metastasis treatment and many other cell migrationrelated diseases. It has been described that specific peptide sequences such as Ile- Gly-Asp (IGD, see Fig. 0-1) and Gly-Arg-Gly-Asp (GRGD) interact with the extracellular matrix (ECM), in particular with Fibronectin protein domains inducing adhesion and migratory behaviour on model cells (MDA-MB-231 metastatic breast cancer cells).[3] Such peptides can be tethered onto Au surfaces by means of self-assembled monolayers (SAMs). It is widely known that alkanethiols on Au surfaces form wellordered and stable SAMs, which represent nowadays the most used model substrate for studying cell behaviour.[4] Recent studies performed in our group proved that IGDbearing peptides induce adhesion and then migratory behaviour on metastatic breast cancer cells.[5,6] The goal of this research project is to use such tuneable scaffolds to mimic the extracellular environment, being able to induce and control cell migration towards an anisotropic surface, for a reversible migration movement. Figure 0-1 – Molecular structures of thiolated peptides bearing the motogenic motif IGDQ (IsoLeu-Gly-Asp-Gln; respecting the biological readability of the sequence) and respective nitrobenzyl photolabile linkers. Two different IGD-bearing peptides will be used to pattern Au surface with two concentration gradients in the opposite direction. A photolabile protecting group will be employed in both peptides. The first peptide will induce the first migration and light irradiation at a specific wavelength will remove the protecting group with its motogenic sequence, therefore exposing the opposite gradient towards the surface, for the second migration to occur

Unfolding IGDQ peptides for engineering motogenic interfaces

Extracellular matrix (ECM)-mimicking surfaces are pivotal tools in understanding adherent cell physiopathology. In this sense, we have recently reported on a discrete set of ECM-mimicking SAMs, among which only those exposing IGDQ peptide-alkanethiols sustain the adhesion of MDA-MB-231 cells by triggering FAK phosphorylation and peculiarly induce the migration of individual cancer cells on the subcentimeter scale. Starting from the experimentally observed relationship among the SAM composition, organization, and biological response, a systematic computational characterization aided in pinpointing the atomistic details through which specific composition and organization achieve the desired biological responsiveness. Specifically, the solvent, number and type of peptides, and presence or absence of surface fillers were accurately considered, creating representative model SAMs simulated by means of classical molecular dynamics (MD) with a view toward unravelling the experimental evidence, revealing how the conformational and structural features of these substrates dictate the specific motogenic responses. Through complementary experimental and computational investigations, it clearly emerges that there exists a distinct and precise mutual interaction among IGDQ-peptides, the surface fillers, and Au, which controls the structural properties of the ECM-mimicking SAMs and thus their motogenic potential

IGDQ motogenic peptide gradient induces directional cell migration through integrin (αv)β3 activation in MDA-MB-231 metastatic breast cancer cells

In the context of breast cancer metastasis study, we have shown in an in vitro model of cell migration that IGDQ-exposing (IsoLeu-Gly-Asp-Glutamine type I Fibronectin motif) monolayers (SAMs) on gold sustain the adhesion of breast cancer MDA-MB-231 cells by triggering Focal Adhesion Kinase and integrin activation. Such tunable scaffolds are used to mimic the tumor extracellular environment, inducing and controlling cell migration. The observed migratory behavior induced by the IGDQ-bearing peptide gradient along the surface allows to separate cell subpopulations with a “stationary” or “migratory” phenotype. In this work, we knocked down the integrins α5(β1) and (αv)β since they are already known to be implicated in cell migration. To this aim, a whole proteomic analysis was performed in beta 3 integrin (ITGB3) or alpha 5 integrin (ITGA5) knock-down MDA-MB-231 cells, in order to highlight the pathways implied in the integrin-dependent cell migration. Our results showed that i) ITGB3 depletion influenced ITGA5 mRNA expression, ii) ITGB3 and ITGA5 were both necessary for IGDQ-mediated directional single cell migration and iii) integrin (αv)β3 was activated by IGDQ fibronectin type I motif. Finally, the proteomic analysis suggested that co-regulation of recycling transport of ITGB3 by ITGA5 is potentially necessary for directional IGDQ-mediated cell migration

Indacaterol inhibits collective cell migration and IGDQ-mediated single cell migration in metastatic breast cancer MDA-MB-231 cells

Summary: Metastasis is the main cause of deaths related to breast cancer. This is particular the case for triple negative breast cancer. No targeted therapies are reported as efficient until now. The extracellular matrix, in particular the fibronectin type I motif IGDQ, plays a major role in regulating cell migration prior metastasis formation. This motif interacts with specific integrins inducing their activation and the migratory signal transduction.Here, we characterized the migratory phenotype of MDA-MB-231 cells, using functionalized IGDQ-exposing surfaces, and compared it to integrin A5 and integrin B3 knock-down cells. A multiomic analysis was developed that highlighted the splicing factor SRSF6 as a putative master regulator of cell migration and of integrin intracellular trafficking. Indacaterol-induced inhibition of SRSF6 provoked: i) the inhibition of collective and IGDQ-mediated cell migration and ii) ITGA5 sequestration into endosomes and lysosomes. Upon further studies, indacaterol may be a potential therapy to prevent cell migration and reduce metastasis formation in breast cancer. 1CRnmBvVXp9LXQy1nJKbUFVideo Abstrac

Outcomes in Newly Diagnosed Atrial Fibrillation and History of Acute Coronary Syndromes: Insights from GARFIELD-AF

BACKGROUND: Many patients with atrial fibrillation have concomitant coronary artery disease with or without acute coronary syndromes and are in need of additional antithrombotic therapy. There are few data on the long-term clinical outcome of atrial fibrillation patients with a history of acute coronary syndrome. This is a 2-year study of atrial fibrillation patients with or without a history of acute coronary syndromes

Analysis of Outcomes in Ischemic vs Nonischemic Cardiomyopathy in Patients With Atrial Fibrillation A Report From the GARFIELD-AF Registry

IMPORTANCE Congestive heart failure (CHF) is commonly associated with nonvalvular atrial fibrillation (AF), and their combination may affect treatment strategies and outcomes