title: Chemical modifications in the seed region of miRNAs 221/222 increase the silencing performances in gastrointestinal stromal tumor cells.
abstract: Most GastroIntestinal Stromal Tumors (GISTs) are characterized by KIT gene overexpression, which in turn is regulated by levels of microRNA 221 and microRNA 222. GISTs can also be distinguished by their miRNAs expression profile in which miRNAs 221/222 result reduced in comparison with GI normal tissues. In this paper, to restore normal miRNAs levels and to improve the silencing performances of miRNAs 221/222, new miRNA mimics in which guide strands are modified by Phosphorothioate (PS) and/or 2'-O-methyl RNA (2'-OMe) inside and outside the seed region, were synthesized and tested in GIST48 cells. We evaluated the positional effect of the chemical modifications on the miRNAs silencing activity, compared to natural and several commercial miRNA mimics. Our results show that chemically modified miRNAs 221/222 with alternating 2'-OMe-PS and natural nucleotides in the seed region are effective inhibitors of KIT gene expression and exhibit increased stability in rat plasma. Besides, their transfection in GIST 48 cells showed significant effects on different cellular processes in which KIT plays a functional role for tumor development (such as migration, cell proliferation, and apoptosis). Therefore, modified miRNAs 221/222 may provide an alternative therapeutic option for GIST treatment also aimed to overcome drug resistance concerns.
authors: Institute of Genetic and Biophysics "Adriano Buzzati Traverso", CNR, Via Pietro Castellino 111, 80131 Naples, Italy.
authors: Montano
authors: M
authors: Durso
authors: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy.
authors: Maria
authors: M
authors: Gaglione
authors: National Research Council-CNR, Institute of Crystallography-IC, Via G. Amendola, 122/O, 70126 Bari, Italy.
authors: Linda
authors: L
authors: Piras
authors: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy.
authors: Maria Emilia
authors: ME
authors: Mercurio
authors: Institute of Genetic and Biophysics "Adriano Buzzati Traverso", CNR, Via Pietro Castellino 111, 80131 Naples, Italy.
authors: Sara
authors: S
authors: Terreri
authors: Institute of Genetic and Biophysics "Adriano Buzzati Traverso", CNR, Via Pietro Castellino 111, 80131 Naples, Italy.
authors: Michele
authors: M
authors: Olivieri
authors: Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Napoli, Italy.
authors: Luciana
authors: L
authors: Marinelli
authors: Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Napoli, Italy.
authors: Ettore
authors: E
authors: Novellino
authors: Fondazione IRCCS SDN, Naples, Italy.
authors: Mariarosaria
authors: M
authors: Incoronato
authors: Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Napoli, Italy.
authors: Paolo
authors: P
authors: Grieco
authors: Bioker srl, Multimedica spa, Naples, Italy.
authors: Gaetano
authors: G
authors: Orsini
authors: Bioker srl, Multimedica spa, Naples, Italy.
authors: Giancarlo
authors: G
authors: Tonon
authors: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy. Electronic address: anna.messere@unina2.it.
authors: Anna
authors: A
authors: Messere
authors: Institute of Genetic and Biophysics "Adriano Buzzati Traverso", CNR, Via Pietro Castellino 111, 80131 Naples, Italy. Electronic address: cimmino@igb.cnr.it.
authors: Amelia
authors: A
authors: Cimmino
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics* / Q000473:pathology*; D020868:Gene Silencing / Q000187:drug effects*; D035683:MicroRNAs / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D010710:Phosphates / Q000494:pharmacology*; D051381:Rats
chemical_list: D035683:MicroRNAs; D010710:Phosphates; C083120:phosphorodithioic acid
keywords: Chemically modified miR221/222; GIST treatment; Inhibitors of KIT gene expression; Therapeutic miRNAs; miRNA mimics