title: Inhibition of Gastric Tumor Cell Growth Using Seed-targeting LNA as Specific, Long-lasting MicroRNA Inhibitors.
abstract: MicroRNAs regulate eukaryotic gene expression upon pairing onto target mRNAs. This targeting is influenced by the complementarity between the microRNA "seed" sequence at its 5' end and the seed-matching sequences in the mRNA. Here, we assess the efficiency and specificity of 8-mer locked nucleic acid (LNA)-modified oligonucleotides raised against the seeds of miR-372 and miR-373, two embryonic stem cell-specific microRNAs prominently expressed in the human gastric adenocarcinoma AGS cell line. Provided that the pairing is perfect over all the eight nucleotides of the seed and starts at nucleotide 2 or 1 at the microRNA 5' end, these short LNAs inhibit miR-372/373 functions and derepress their common target, the cell cycle regulator LATS2. They decrease cell proliferation in vitro upon either transfection at nanomolar concentrations or unassisted delivery at micromolar concentrations. Subcutaneously delivered LNAs reduce tumor growth of AGS xenografts in mice, upon formation of a stable, specific heteroduplex with the targeted miR-372 and -373 and LATS2 upregulation. Their therapeutic potential is confirmed in fast-growing, miR-372-positive, primary human gastric adenocarcinoma xenografts in mice. Thus, microRNA silencing by 8-mer seed-targeting LNAs appears a valuable approach for both loss-of-function studies aimed at elucidating microRNA functions and for microRNA-based therapeutic strategies.
authors.affiliation: 1] University of Bordeaux, ARNA Laboratory, Bordeaux, France [2] INSERM, U869, Bordeaux, France.
authors.forename: Cathy
authors.initials: C
authors.lastname: Staedel
authors.affiliation: 1] University of Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Varon
authors.affiliation: 1] University of Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France.
authors.forename: Phu Hung
authors.initials: PH
authors.lastname: Nguyen
authors.affiliation: 1] University of Bordeaux, ARNA Laboratory, Bordeaux, France [2] INSERM, U869, Bordeaux, France.
authors.forename: Brune
authors.initials: B
authors.lastname: Vialet
authors.affiliation: 1] University of Bordeaux, Laboratoire de Bactériologie, Bordeaux, France [2] INSERM, U853, Bordeaux, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Chambonnier
authors.affiliation: University of Bordeaux, Service Commun des Animaleries, Bordeaux, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Rousseau
authors.affiliation: 1] Department of Biopathology, Institut Bergonié, Bordeaux, France [2] INSERM, U916, Bordeaux, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Soubeyran
authors.affiliation: Digestive Tumors Unit, Institut Bergonié, Bordeaux Cedex, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Evrard
authors.affiliation: 1] University of Bordeaux, Résonance Magnétique des Systèmes Biologiques, Bordeaux, France [2] CNRS, UMR 5536, Bordeaux, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Couillaud
authors.affiliation: 1] University of Bordeaux, ARNA Laboratory, Bordeaux, France [2] INSERM, U869, Bordeaux, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Darfeuille