MASS SPECTROMETRY AS A BIOANALYTICAL TOOL FOR QUANTITATIVE PROTEOMIC AND SMALL MOLECULE ANALYSIS: INVESTIGATING CELL-CELL INTERACTIONS AND BODY FLUIDS

Abstract

Chemoresistance is a major failure of chemotherapy. Understanding the mechanisms behind chemoresistance will benefit the development of anticancer drugs and clinical treatment. However, there is a lack of comprehensive understanding of chemoresistance at protein and metabolite levels. Nowadays, mass spectrometry (MS) has proven to be a powerful tool for metabolic and proteomic studies, significantly promoting studies of chemoresistance from multiple aspects, such as screening potential biomarkers, identifying drug targets, and investigating relevant proteomic and metabolomic pathways, that can eventually combat chemoresistance in cancer treatment. My PhD studies are focused on MS studies of chemoresistance, specifically using cell lines to investigate drug uptake and cell-cell interactions, as well as the development of high-abundant protein depletion methods for improved detection of low-abundance proteins in cross-species biofluids. This thesis contains four chapters. The first chapter is a short review of current studies on cell-cell interactions using MS techniques. The second chapter is primarily about MS proteomics studies cell-cell communication between drug-sensitive and drug-resistant cancer cells. We found that regular cancer cells could gain drug resistance through cell-cell communication. We also analyzed related metabolites and proteins using the Single-probe single cell MS and label-free bottom-up proteomics methods, respectively. In the third chapter, we established a novel method using LC-MS to quantify drug uptake in single spheroids, potentially promoting studies in understanding chemoresistance in ovarian cancer treatments. Chapter four focuses on evaluating multiple methods for depleting abundant proteins in serums across different species, allowing for improved detection sensitivity of low-abundance proteins.