Development of a DELFIA method to detect oncofetal antigen ROR1-positive exosomes

Biochem Biophys Res Commun. 2021 Nov 12;578:170-176. doi: 10.1016/j.bbrc.2021.08.054. Epub 2021 Aug 24.


Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is highly expressed in a wide variety of hematological and solid cancers, but is low or absent in adult tissues. Here, we show that ROR1 is released with exosomes from ROR1-positive cancer cells. We also developed a simple dissociation-enhanced lanthanide fluorescence immunoassay (DELFIA) to detect cancer-derived ROR1-positive exosomes, which are captured by two anti-ROR1 antibodies and detected by the fluorescence of free chelating europium. This new DELFIA method can detect cancer-derived ROR1-positive exosomes in the cell supernatant and serum with a wide range and rapidly compared with the conventional Western blot assay. This method may be useful as a companion diagnostics for ROR1-positive cancers.

Keywords: DELFIA; Diagnostics; Exosomes; ROR1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Neoplasm / metabolism*
  • Biomarkers, Tumor / blood*
  • Biomarkers, Tumor / metabolism
  • Cell Line, Tumor
  • Disease Models, Animal
  • Exosomes / metabolism
  • Exosomes / pathology*
  • Female
  • Humans
  • Immunoassay / methods*
  • Mice
  • Mice, Inbred BALB C
  • Neoplasms / blood
  • Neoplasms / metabolism
  • Neoplasms / pathology*
  • Receptor Tyrosine Kinase-like Orphan Receptors / metabolism*


  • Antigens, Neoplasm
  • Biomarkers, Tumor
  • oncofetal antigens
  • ROR1 protein, human
  • Receptor Tyrosine Kinase-like Orphan Receptors