Recognition of nucleolin through interaction with RNA G-quadruplex

Julho 2021

The development of novel biomarkers for early-stage diagnosis of prostate cancer (PCa) has attracted the attention of researchers in the last decade. Nucleolin (NCL) has emerged as a possible biomarker of PCa due to its high expression levels in the surface of PCa cells and affinity towards parallel G4s since it contains four RNA-binding domains (RBDs). Herein, we developed a novel strategy based on a microfluidic platform for the detection of NCL in biological samples, such as human plasma. The RNA G4 (rG4) sequence found in human precursor microRNA 92b (pre-miR-92b) was used as a molecular recognition probe since it forms a single dominant parallel rG4 conformation in the presence of 0.1 mM K+ as confirmed by NMR spectroscopy. The additional stability of the rG4 structure was provided by the acridine orange derivative ligand C8, which stabilizes the pre-miR-92b rG4 structure, as denoted by an increase in more than 30 °C of its melting temperature. FRET-melting assay revealed a remarkable synergistic effect of NCL RBD1,2 and C8 on the stabilization of the pre-miR-92b rG4. The binding of pre-miR-92b to NCL RBD1,2 was determined by in silico studies, which revealed a binding pocket formed by a 12-residue linker between RBD1 and RBD2. Both, pre-miR-92b rG4 and pre-miR-92b rG4/C8 complex demonstrated high affinity towards NCL RBD1,2, as proved by fluorimetric titrations (KD range between 10-12 and 10-9 M). The stability and nuclease resistance of pre-miR-92b rG4 and pre-miR-92b rG4/C8 complex were evaluated as molecular recognition probes to capture and detect NCL. Finally, the microfluidic platform detects NCL in complex biological samples, such as human plasma. Overall, this work demonstrates the usefulness of the microfluidic platform based on the pre-miR-92b to detect NCL and the possibility to be used as a valuable biomedical tool in PCa diagnosis.

Autores da comunidade :

• 

  M

  Maria Paula Cordeiro Crespo Cabral Campello Aboim de Barros

  ist25375

  Afiliações e fontes

  IST > DECN

  Departamento de Engenharia e Ciências Nucleares

  IST > C2TN

  Centro de Ciências e Tecnologias Nucleares

  De: orcid

  ID: 82294704

  De: cienciavitae

  ID: 2059763

• 

  A

  António Manuel Rocha Paulo

  ist126677

  Afiliações e fontes

  IST > DECN

  Departamento de Engenharia e Ciências Nucleares

  IST > C2TN

  Centro de Ciências e Tecnologias Nucleares

  De: orcid

  ID: 82180456

  De: cienciavitae

  ID: 2055512

AO - Versão original do autor

Elsevier

https://www.sciencedirect.com/journal/biochemical-pharmacology

Biochemical Pharmacology

114208

189

0006-2952

10.1016/j.bcp.2020.114208

WOS:000662577800008

chemical-sciences - Química

Palavras-chave

• Nucleolin
• RNA G-quadruplex
• Acridine ligands
• Microfluidics and Prostate cancer

eng - Inglês

http://dx.doi.org/10.1016/j.bcp.2020.114208