Evaluation of nucleosome concentrations in healthy dogs and dogs with cancer

PLoS One. 2020 Aug 31;15(8):e0236228. doi: 10.1371/journal.pone.0236228. eCollection 2020.

Abstract

Introduction: Nucleosomes consist of small fragments of DNA wrapped around a histone octamer core. Diseases such as cancer or inflammation lead to cell death, which causes fragmentation and release of nucleosomes into the blood. The Nu.Q™ technology measures circulating nucleosome levels and exploits the different compositions of cancer derived nucleosomes in blood to detect and identify cancer even at early stages. The objectives of this study are to identify the optimal sample type for the Nu.Q™ H3.1 assay and to determine if it can accurately detect nucleosomes in the blood of healthy canines as well as those with cancer.

Materials and methods: Blood samples from healthy canine volunteers as well as dogs newly diagnosed with lymphoma were used. The blood was processed at a variety of times under a variety of conditions to determine the most reliable sample type and conditions, and to develop an appropriate processing strategy to ensure reliably accurate results.

Results: Nucleosomes could be detected using a variety of sample collection and processing protocols. Nucleosome signals were highest in EDTA plasma and serum samples and most consistent in plasma. Samples should be processed within an hour of collection. Experiments showed that samples were able to withstand several freeze thaw cycles. Processing time and tcollection tube type did affect nucleosome detection levels. Finally, significantly elevated concentrations of nucleosomes were seen in a small cohort of dogs that had been newly diagnosed with lymphoma.

Conclusions: When samples are collected and processed appropriately, the Nu.Q™ platform can reliably detect nucleosomes in the plasma of dogs. Further testing is underway to validate and optimize the Nu.Q™ platform for veterinary use.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dogs
  • Enzyme-Linked Immunosorbent Assay / instrumentation
  • Enzyme-Linked Immunosorbent Assay / methods
  • Feasibility Studies
  • Female
  • Lymphoma / blood
  • Lymphoma / diagnosis*
  • Lymphoma / veterinary*
  • Male
  • Nucleosomes*
  • Reagent Kits, Diagnostic / veterinary*
  • Reproducibility of Results

Substances

  • Nucleosomes
  • Reagent Kits, Diagnostic

Grants and funding

Funding for materials and author salaries was provided by Belgian Volition SPRL. HWR and TM received salary from these funds. JT, TK, ND, MH, TB, NH and GM are employees of Belgian Volition & Volition America. The URL to the Belgian Volition website is: https://volition.com/. Some additional funding for HWR and TM salaries was provided by the Fred and Vola Palmer Chair of Comparative Oncology held by HWR.