title: Influence of conformationally restricted pyrimidines on the activity of 10-23 DNAzymes.
abstract: The catalytic core of a 10-23 DNAzyme was modified introducing conformationally restricted nucleosides such as (2'R)-, (2'S)-2'-deoxy-2'-C-methyluridine, (2'R)-, (2'S)-2'-deoxy-2'-C-methylcytidine, 2,2'-anhydrouridine and LNA-C, in one, two or three positions. Catalytic activities under pseudo first order conditions were compared at different Mg(2+) concentrations using a short RNA substrate. At low Mg(2+) concentrations, triple modified DNAzymes with similar kinetic performance to that displayed by the non-modified control were identified. In the search for a partial explanation of the obtained results, in silico studies were carried out in order to explore the conformational behavior of 2'-deoxy-2'-C-methylpyrimidines in the context of a loop structure, suggesting that at least partial flexibility is needed for the maintenance of activity. Finally, the modified 2'-C-methyl DNAzyme activity was tested assessing the inhibition of Stat3 expression and the decrease in cell proliferation using the human breast cancer cell line T47D.
authors.affiliation: INGEBI (CONICET), Vuelta de Obligado 2490-(1428), Buenos Aires, Argentina.
authors.forename: Laura
authors.initials: L
authors.lastname: Robaldo
authors.forename: Franco
authors.initials: F
authors.lastname: Izzo
authors.forename: María
authors.initials: M
authors.lastname: Dellafiore
authors.forename: Cecilia
authors.initials: C
authors.lastname: Proietti
authors.forename: Patricia V
authors.initials: PV
authors.lastname: Elizalde
authors.forename: Javier M
authors.initials: JM
authors.lastname: Montserrat
authors.forename: Adolfo M
authors.initials: AM
authors.lastname: Iribarren
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D055162:Biocatalysis; D049109:Cell Proliferation / Q000187:drug effects; D021881:DNA, Catalytic / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D008968:Molecular Conformation; D011743:Pyrimidines / Q000737:chemistry / Q000494:pharmacology*; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D021881:DNA, Catalytic; D004277:DNA, Single-Stranded; D011743:Pyrimidines; C402582:RNA-cleaving DNA 10-23; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human