PROJECT SUMMARY
Ovarian cancer is a silent killer that strikes with few, if any, symptoms. By the time a woman knows she has it,
the cancer is often advanced and the outlook grim. However, if epithelial ovarian cancer is caught early the
prognosis for the patient is excellent. Developing non-invasive and highly specific blood-based tests for pre-
symptomatic screening and early detection of ovarian cancer is therefore crucial. This is especially essential
since obtaining a biopsy is difficult, costly, and sometimes not even an option. In addition, most blood biomarkers
to date lack the necessary sensitivity and specificity for early detection of this silent killer. A fundamental
challenge is the extremely low concentrations of circulating biomolecules released from the developing tumors
at pre-clinical stages which can be 10,000-fold lower than their clinically detectable levels. Therefore, there is a
pressing need to uncover novel biomarkers, apply new strategies, and develop robust technologies to propel the
advancement of cancer diagnostics, especially in a disease such as ovarian cancer. We have focused our efforts
on small extracellular vesicles (sEVs), primarily small and large exosomes derived from the endolysosomal
pathway, which play important roles in cellular communication, immune response, and cancer progression via
transfer of a selective repertoire of biomolecules. sEVs/exosome release is significantly increased in most
neoplastic cells, including ovarian cancer and occurs continuously at all stages of tumor development. Tumor-
derived sEVs accumulate in human blood and malignant effusions. These vesicles carry enriched subsets of
biomolecules mirroring the tumor cells of origin, such as signaling proteins, tumor antigens, and functional RNAs
(mRNA and miRNAs), which offer a new strategy to surmount the challenge in reliable detection of intrinsically
low-level serum markers during early malignant transformation. Thus, the constitutive release and enrichment
of certain tumor markers within sEVs present distinctive opportunities for early cancer diagnosis. We
hypothesize that circulating sEVs, much akin to circulating tumor cells but more robust due to their active release
and incredible stability in bodily fluids, represent a greater source for the discovery of exo-biomarkers for early
detection, potentially while still confined to the fallopian tube. In addition, sEVs can serve as a 'liquid biopsy’ to
assess benefits and treatment responses in real time in cancer patients. Our innovative application merges EV
biology with nano-material/microfluidic technology to develop an advanced microfluidic platform to capture and
detect ovarian cancer-derived sEVs with high specificity and sensitivity from the circulation. This approach will
integrate validated fallopian tube and ovarian cancer associated exo-protein biomarkers (SA1), which will be
applied to a second-generation nano-engineered EV analysis chip (SA2). These studies will be followed by
clinical validation using longitudinal samples collected from asymptomatic women who later develop epithelial
ovarian cancer (SA3). Our ultimate goal is to develop a reliable blood-based assay that, when used in
conjunction with current screening approaches will decrease the mortality from ovarian cancer.