Circulating DNA reveals nucleosome occupancy patterns that are associated with nucleosome-DNA affinity and are affected in cancer

Comprehensive Summary

Cell-free circulating DNA fragments form liquid biopsies has been increasingly studies for its potential use as a biomarker as they can originate from cells in many tissues, most often hematopoietic cells. The researchers obtained genomic positions of the circulating DNA fragments from patients with and without cancer to analyze these fragments across the two populations. They found that nucleosome occupancy was associated with histone-DNA affinity, differing across healthy and cancer samples. In addition, they found that the fragment biomarkers for cancer were generally similar, with distinct cancers having their own specific features. The discovery of well-positioned nucleosomes at transcription factor binding sites showed pan-cancer regulation of these programs affecting the main circulating DNA sources. This research allows for future use of circulating DNA fragments as a physical readout of cancer from liquid biopsies.

Outcomes and Implications

The usage of circulating DNA fragments for cancer detection allows for a minimally invasive technique to detect cancer early. These liquid biopsies allow for a complete profile to be built regarding the tumor to allow for a more complete genetic profile to be built. Additionally, these fragments can be used to monitor how tumors respond to treatment plans and can minimize the use of residual disease testing for recurrence.