Assessing specific oligonucleotides and small molecule antibiotics for the ability to inhibit the CRD-BP-CD44 RNA interaction

PLoS One. 2014 Mar 12;9(3):e91585. doi: 10.1371/journal.pone.0091585. eCollection 2014.

Abstract

Studies on Coding Region Determinant-Binding Protein (CRD-BP) and its orthologs have confirmed their functional role in mRNA stability and localization. CRD-BP is present in extremely low levels in normal adult tissues, but it is over-expressed in many types of aggressive human cancers and in neonatal tissues. Although the exact role of CRD-BP in tumour progression is unclear, cumulative evidence suggests that its ability to physically associate with target mRNAs is an important criterion for its oncogenic role. CRD-BP has high affinity for the 3'UTR of the oncogenic CD44 mRNA and depletion of CRD-BP in cells led to destabilization of CD44 mRNA, decreased CD44 expression, reduced adhesion and disruption of invadopodia formation. Here, we further characterize the CRD-BP-CD44 RNA interaction and assess specific antisense oligonucleotides and small molecule antibiotics for their ability to inhibit the CRD-BP-CD44 RNA interaction. CRD-BP has a high affinity for binding to CD44 RNA nts 2862-3055 with a Kd of 645 nM. Out of ten antisense oligonucleotides spanning nts 2862-3055, only three antisense oligonucleotides (DD4, DD7 and DD10) were effective in competing with CRD-BP for binding to 32P-labeled CD44 RNA. The potency of DD4, DD7 and DD10 in inhibiting the CRD-BP-CD44 RNA interaction in vitro correlated with their ability to specifically reduce the steady-state level of CD44 mRNA in cells. The aminoglycoside antibiotics neomycin, paramomycin, kanamycin and streptomycin effectively inhibited the CRD-BP-CD44 RNA interaction in vitro. Assessing the potential inhibitory effect of aminoglycoside antibiotics including neomycin on the CRD-BP-CD44 mRNA interaction in cells proved difficult, likely due to their propensity to non-specifically bind nucleic acids. Our results have important implications for future studies in finding small molecules and nucleic acid-based inhibitors that interfere with protein-RNA interactions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Aminoglycosides / chemistry
  • Aminoglycosides / pharmacology*
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Base Sequence
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / genetics
  • HeLa Cells
  • Humans
  • Hyaluronan Receptors / chemistry
  • Hyaluronan Receptors / genetics*
  • Oligonucleotides, Antisense / genetics*
  • Peptide Fragments / metabolism
  • Protein Binding / drug effects
  • Protein Binding / genetics
  • RNA-Binding Proteins / metabolism*

Substances

  • 3' Untranslated Regions
  • Aminoglycosides
  • Anti-Bacterial Agents
  • Hyaluronan Receptors
  • IGF2BP1 protein, human
  • Oligonucleotides, Antisense
  • Peptide Fragments
  • RNA-Binding Proteins

Grants and funding

This work was supported by a Discovery Grant (grant number 227158) from Natural Sciences & Engineering Research Council (NSERC) to C.H.L. D.T.K. was a recipient of NSERC Undergraduate Student Research Awards and a BC Cancer Agency Summer Studentship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.