Exosomal (exo) dsDNA as a diagnostic and prognostic tool in pediatric solid tumours

Introduction:

The traditional tumour biopsy can be painful due to being an invasive procedure. In addition, tumour biopsies do not always give a full picture of the tumour heterogeneity. Therefore, we endeavor to develop a diagnostic and prognostic liquid biopsy tool using exo-dsDNA, obtained by a simple, pain-free blood draw.

Methods:

Using size exclusion chromatography or ultracentrifugation, exosomes were isolated from cell line conditioned media and PDX mouse plasma of the cancer models Retinoblastoma and Rhabdoid tumour. Exosomes were characterised using BCA, Zeta View and electron microscopy. The exo-dsDNA was extracted using a QIAGEN microkit and analysed for disease associated mutations using sequencing or PCR techniques.

Results:

Disease associated mutations were detectable in the cell line exo-dsDNA. Analysis of mouse plasma and patient plasma exo-dsDNA is in progress.

Conclusion:

These results show the potential of using exo-dsDNA as a diagnostic or prognostic tool in solid tumours.