Nucleic Acid Targeted Therapy: G4 Oligonucleotides Downregulate HRAS in Bladder Cancer Cells through a Decoy Mechanism

Giulia Miglietta; Alaa S Gouda; Susanna Cogoi; Erik B Pedersen; Luigi E Xodo

doi:10.1021/acsmedchemlett.5b00315

Nucleic Acid Targeted Therapy: G4 Oligonucleotides Downregulate HRAS in Bladder Cancer Cells through a Decoy Mechanism

ACS Med Chem Lett. 2015 Oct 18;6(12):1179-83. doi: 10.1021/acsmedchemlett.5b00315. eCollection 2015 Dec 10.

Authors

Giulia Miglietta¹, Alaa S Gouda², Susanna Cogoi¹, Erik B Pedersen², Luigi E Xodo¹

Affiliations

¹ Department of Medical and Biological Sciences, University of Udine , 33100 Udine, Italy.
² Nucleic Acid Center, Institute of Physics and Chemistry, University of Southern Denmark , DK-5230 Odense M, Denmark.

Abstract

In a previous study we have demonstrated that two neighboring G-quadruplexes, hras-1 and hras-2, located immediately upstream of the major transcription start site of HRAS, bind MAZ, a nuclear factor that activates transcription (Cogoi, S.; et al. Nucl. Acid Res. 2014, 42, 8379). For the present study we have designed G4 oligonucleotides with anthraquinone insertions and locked nucleic acids (LNA) modifications mimicking quadruplex hras-1. Luciferase, qRT-PCR, and Western blot data demonstrate that these constructs efficiently down regulate HRAS in T24 bladder cancer cells. The inhibitory efficiency of the G4 oligonucleotides correlates with their nuclease resistance in the cell environment. By chromatin immunoprecipitation we show that the association of MAZ to the HRAS promoter is strongly attenuated by the designed G4 oligonucleotides, thus suggesting that these constructs behave with a decoy mechanism.

Keywords: G4-oligonucleotides; HRAS; T24 bladder cancer cells; anthraquinone insertions; decoy mechanism.