Advancing Ovarian Cancer Diagnostics: Discovering Potential Protein Biomarkers in Extracellular Vesicles

High grade serous ovarian carcinoma (HGSOC) accounts for ~70% of ovarian cancer cases. Non-invasive, highly specific blood-based tests for pre-symptomatic screening in women are crucial to reducing the mortality associated with this disease. The goal of these studies was to uncover novel biomarkers associated with tumor-derived extracellular vesicles (EVs) to advance ovarian cancer diagnostics.In the work presented in this dissertation, I show that EVs from plasma and tissues are rich in proteins (exo-proteins), which can potentially be exploited to develop a liquid-based biopsy for early detection and disease monitoring. In the first study, we performed proteomic analysis using liquid chromatography with tandem mass spectrometry (LC-MS/MS) on plasma EVs from HGSOC patients (n=10) and matching healthy controls (n=10). From this, 1,973 exo-proteins were identified, and 16 exo-proteins were significantly upregulated in the blood plasma of HGSOC patients. We confirmed the presence of these proteins using capillary western blotting (Wes) and this narrowed it down to five potential candidate biomarkers: APEH, CPNE3, FARSA, MSLN and PSMB9. However, subsequent ELISA showed that the exo-protein concentrations of these four candidates did not differ significantly in a small case-control study. As a result, this led us to our second study to explore alternative sources of EVs, focusing on those derived from tissues and cell lines. Given that majority of HGSOCs typically arise from the fallopian tubes (FT), our biomarker search concentrated on proteins present on the surface of EVs released by both FT and HGSOC tissue explants and representative cell lines. Using LC-MS/MS, 985 exo-proteins were identified that comprised the FT/HGSOC EV core proteome. Transmembrane exo-proteins were prioritized because these could serve as antigens for capture and/or detection. With a nano-engineered microfluidic platform, six newly discovered exo-proteins (ACSL4, IGSF8, ITGA2, ITGA5, ITGB3, MYOF) plus a known HGSOC associated protein, FOLR1 exhibited classification performance ranging from 85-98% in a case-control study using plasma samples representative of early and late stage HGSOCs. Furthermore, by linear combination of IGSF8 and ITGA5 based on logistic regression analysis, we achieved a sensitivity of 80% with 99.8% specificity. These lineage-associated exo-biomarkers have potential to detect cancer while localized to the FT when patient outcomes are more favorable.

Grantor dc:publisher

University of Kansas

Year dc:date.issued

2023

Author dc:creator

• Trinidad, Camille Visco

Advisor dc:contributor.advisor

• Godwin, Andrew K.

• Pathology
• Biomedical engineering
• Oncology
• biomarker
• extracellular vesicles
• fallopian tube
• microfluidics
• ovarian cancer
• proteomics

Statement dc:rights

• Copyright held by the author.

Language dc:language.iso

en

Dc Identifier Other

http://dissertations.umi.com/ku:19100

OAI identifier oai:identifier

oai:kuscholarworks.ku.edu:1808/37312