Affiliations: Université de Reims Champagne Ardenne, CNRS 6237 MEDyC, Laboratoire SiRMa, IFR 53 Interactions Cellules-Microenvironnement, Reims, France | Université d'Angers, SONAS, UFR Sciences Pharmaceutiques et Ingénierie de la Santé, Angers, France
Note: [] Corresponding author: Jérôme Devy, Université de Reims Champagne Ardenne, UMR CNRS 6237 MEDyC, Laboratoire SiRMa, IFR 53 Interactions Cellules-Microenvironnement, Moulin de la Housse, BP 1039, 51687 Reims, France. Tel.: +33 3 03 26 91 33 49; Fax: +33 3 03 26 91 83 66; E-mail: [email protected]
Abstract: Background: Leukemic cell adhesion to proteins of the bone marrow microenvironment provides signals which control morphology, motility and cell survival. We described herein the ability of ethoxyfagaronine (etxfag), a soluble synthetic derivative of fagaronine, to prevent leukemic cell adhesion to fibronectin peptide (FN/V). Methods: Phosphorylation of fak and pyk2 were evaluated by immunoblotting. Labelled proteins were localized by confocal microscopy. PI 3-kinase activity was evaluated by in vitro kinase assay. Results: Subtoxic concentration of etxfag reduced L1210 cell adhesion to FN/V dependently of β1 integrin engagement. Etxfag impaired FN-dependent formation of β1 clustering without modifying β1 expression at the cell membrane. This was accompanied by a decrease of focal adhesion number, a diminution of fak and pyk2 phosphorylation at Tyr-576, Tyr-861 and Tyr-579, respectively leading to their dissociations from β1 integrin and inhibition of PI 3-kinase activity. Etxfag also induced a cell retraction accompanied by a redistribution of phosphorylated fak and pyk2 in the perinuclear region and lipid raft relocalization. Conclusion: Through its anti-adhesive potential, etxfag, combined with conventional cytotoxic drugs could be potentially designed as a new anti-leukemic drug.
