Developing slow-off dickkopf-1 aptamers for early-diagnosis of hepatocellular carcinoma

Talanta. 2019 Mar 1:194:422-429. doi: 10.1016/j.talanta.2018.10.014. Epub 2018 Oct 11.

Abstract

In this work, we obtained fast-off and slow-off aptamer recognizing dickkopf-1(DKK1), a promising biomarker for detection of early-stage hepatocellular carcinoma (HCC), with high affinity in a single SELEX procedure. The two types of aptamer possessed distinct characteristics confirmed via different validation methods. In comparison to fast-off aptamers, slow-off aptamers were proven more suitable for aptamer-based ELISA assay. Using slow dissociation SELEX, slow-off aptamers were selectively retained. Meanwhile, a mutant (34del) of slow-off D10 was estimated with picomolar affinity (371.9 pM). The mutant was further truncated into 39nt before pairing with an antibody in the aptamer-based ELISA. The aptamer-target-antibody construction showed similar performance as conventional ELISA with a detection limit of 62.5 pg/ml. Quantification in 60 sera samples with the construction was also correlated with conventional ELISA. The results demonstrated novel DKK1 aptamer could replace capture antibody for potential early HCC diagnosis.

Keywords: Aptamer; DKK1; Hepatocellular carcinoma (HCC); SELEX; Slow-off.

MeSH terms

  • Carcinoma, Hepatocellular / diagnosis*
  • Early Detection of Cancer*
  • Humans
  • Intercellular Signaling Peptides and Proteins / chemistry
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Liver Neoplasms / diagnosis*
  • Models, Molecular
  • Protein Conformation
  • SELEX Aptamer Technique*

Substances

  • DKK1 protein, human
  • Intercellular Signaling Peptides and Proteins