title: Systematic Evaluation of Biophysical and Functional Characteristics of Selenomethylene-Locked Nucleic Acid-Mediated Inhibition of miR-21.
abstract: miRNAs constitute an important layer of gene regulation mediated by sequence-specific targeting of mRNAs. Aberrant expression of miRNAs contributes to a host of pathological states. Promoting cancer, miR-21 is upregulated in variety of cancers and promotes tumor progresion by suppressing a network of tumor suppressor genes. Here we describe a novel class of bicyclic RNA analogues, selenomethylene-locked nucleic acid (SeLNA), that display high affinity, improved metabolic stability, and increased potency for miR-21 inhibition. The thermal stability (Tm) for duplexes was increased significantly with incorporation of SeLNA monomers as compared to that of the unmodified DNA-RNA hybrid. A comprehensive thermodynamic profile obtained by isothermal titration calorimetry revealed a favorable increase in the enthalpy of hybridization for SeLNA containing DNA and target RNA heteroduplexes. SeLNA modifications displayed remarkable binding affinity for miR-21 target RNA with a Kaof ≤1.05 × 108M-1. We also observed enhanced serum stability for SeLNA-RNA duplexes with a half-life of ≤36 h. These in vitro results were well correlated with the antisense activity in cancer cells imparting up to ∼91% inhibition of miR-21. The functional impact of SeLNA modifications on miR-21 inhibition was further gauged by investigating the migration and invasion characterisitics of cancer cells, which were drastically reduced to ∼49 and ∼55%, respectively, with SeLNA having four such modifications. Our findings demonstrate SeLNA as a promising candidate for therapeutics for disease-associated miRNAs.
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR) , Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India.|CSIR-Institute of Genomics and Integrative Biology , Mathura Road, Delhi 110025, India.
authors.forename: Smita
authors.initials: S
authors.lastname: Nahar
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR) , Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India.|CSIR-Institute of Genomics and Integrative Biology , Mathura Road, Delhi 110025, India.
authors.forename: Amrita
authors.initials: A
authors.lastname: Singh
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.|National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN) , 7-6-8-Saito-Asagi, Ibaraki, Osaka 567-0085, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Morihiro
authors.affiliation: Graduate School of Pharmaceutical Sciences, Nagoya University , Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Moai
authors.affiliation: Graduate School of Pharmaceutical Sciences, Nagoya University , Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kodama
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University , 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.|National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN) , 7-6-8-Saito-Asagi, Ibaraki, Osaka 567-0085, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Obika
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR) , Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India.|CSIR-Institute of Genomics and Integrative Biology , Mathura Road, Delhi 110025, India.|Organic Chemistry Division, CSIR-National Chemical Laboratory , Pashan Road, Pune 411008, India.
authors.forename: Souvik
authors.identifier: http://orcid.org/0000-0001-9897-1419
authors.initials: S
authors.lastname: Maiti
mesh_terms: D017209:Apoptosis; D015153:Blotting, Western; D002465:Cell Movement; D049109:Cell Proliferation; D002942:Circular Dichroism; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000037:antagonists & inhibitors* / Q000235:genetics; D009841:Oligonucleotides / Q000008:administration & dosage / Q000737:chemistry*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012643:Selenium / Q000737:chemistry*
chemical_list: C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D009841:Oligonucleotides; D012333:RNA, Messenger; C477371:locked nucleic acid; D008156:Luciferases; D012643:Selenium