Extracellular vesicle molecular signatures characterize metastatic dynamicity in ovarian cancer

Late-stage diagnosis of ovarian cancer drastically lowers 5-year survival rate from 90% to 30%. Early screening tools that use non-invasive sampling methods combined with high specificity and sensitivity can significantly increase survival. Emerging research employing blood-based screening tools have shown promise in non-invasive detection of cancer. Our findings in this study show the potential of a small extracellular vesicle (sEV)-derived signature as a non-invasive longitudinal screening tool in ovarian cancer. We identified a 7-gene panel in these sEVs that overlapped with an established tissue-derived metastatic ovarian carcinoma signature. We found the 7-gene panel to be differentially expressed with tumor development and metastatic spread. While there were quantifiable changes in genes from the 7-gene panel in plasma-derived sEVs from ovarian cancer patients, we were unable to establish a definitive signature due to low sample number. The most notable finding was a significant change in the ascites-derived sEV gene signature that overlapped with that of the plasma-derived sEV signature at varying stages of disease progression. Taken together our findings show that differential expression of metastatic genes derived from circulating sEVs present a minimally invasive screening tool for ovarian cancer detection and longitudinal monitoring of molecular changes associated with progression and metastatic spread.