Abstract

Throughout society’s continual war against cancer, we have attempted pharmacological intervention only to find that tumors develop modes of resistance. It is well known that genetics play an integral role in cancer. Technological advances have greatly improved our ability to study cancer biochemistry beyond the genome by measuring changes in the expression and activity of RNA, proteins, and lipids in experimental models and human patients. As our techniques and technology to perform cancer research progresses, it is becoming more evident that cancer cells develop stress tolerance mechanisms at multiple levels within the central dogma, including altering mRNA expression, enzyme concentrations, and functional activity of cellular proteins and lipids. In the first chapter, I review previous discoveries demonstrating the importance of metabolic reprogramming in cancer cells and how shifts in metabolic pathways contribute to cancer progression and therapeutic challenges. I discuss how mass spectrometry is a multifunctional research tool that can be used to identify global shifts in gene expression, identify oncogenic roles of specific metabolites and corresponding metabolic pathways, conduct enzyme activity assays, and understand the effects of drugs on cell signaling and metabolic flux through specific pathways. While metabolic reprogramming is a complex and multifaceted concept, the following chapters focus on two specific stress tolerance pathways of lipid and protein metabolism we have shown to significantly promote cancer cell evolution, proliferation, and drug resistance in models of human pancreatic and colon cancer. I describe novel mass spectrometry-based lipidomics and proteomics methods we developed to measure and determine the biological impact of these pathways in each model. I discuss the contributions we have made toward increasing general knowledge of metabolic reprogramming networks in cancer and how they may be targeted in more specific and effective manners to sensitize cancers to therapeutic drugs. Specifically, the second chapter entails our study of a pro-survival lipid metabolic pathway driven by the sphingolipid modifying enzyme sphingosine kinase in a panel of differentially reprogrammed pancreatic cancer subclones. The third chapter describes our novel kinetic proteomics approach to identify how the cellular degradation system autophagy is used to selectively remodel the proteome of colon tumor cells in a xenograft mouse model of colon cancer. Lastly, I discuss how these and other projects completed during my graduate work lay a foundation for ongoing research to further our fundamental understanding of cancer metabolism and treatment development.

Degree

PhD

College and Department

Physical and Mathematical Sciences; Chemistry and Biochemistry

Rights

http://lib.byu.edu/about/copyright/

Date Submitted

2018-10-01

Document Type

Dissertation

Handle

http://hdl.lib.byu.edu/1877/etd10959

Keywords

foundational cancer research, metabolic reprogramming, clonal evolution, sphingolipid signaling, selective autophagy, mass spectrometry, kinetic proteomics

Language

english

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