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ORCID

http://orcid.org/0000-0003-3091-5909

Date of Award

Summer 8-15-2016

Author's School

Graduate School of Arts and Sciences

Author's Department

Chemistry

Degree Name

Doctor of Philosophy (PhD)

Degree Type

Dissertation

Abstract

It is well established that most cancer cells uptake increased amounts of glucose relative to normal differentiated cells. The majority of this glucose carbon is secreted from the cell as lactate. The fate of the remaining glucose carbon, however, has not been well characterized. Here we applied a novel combination of metabolomic technologies to track uniformly labeled glucose in HeLa cancer cells. We provide a list of specific intracellular metabolites that become enriched after 48 hours of labeling and quantitate the fraction of consumed glucose that ends up in proteins, peptides, sugars/glycerol, and lipids.

Next, we investigated whether the main product of fermenting cells, lactate, has a different fate other than secretion. Here we explored the possibility that cytosolic lactate is metabolized by the mitochondria of fermenting mammalian cells. We found that fermenting HeLa and H460 cells utilize exogenous lactate carbon to synthesize a large percentage of their lipids. With high-resolution mass spectrometry, we found that both 13C and 2-2H labels from enriched lactate enter the mitochondria. The lactate dehydrogenase (LDH) inhibitor oxamate decreased respiration of isolated mitochondria incubated in lactate, but not isolated mitochondria incubated in pyruvate. Additionally, transmission electron microscopy (TEM) showed that LDHB localizes to the mitochondria. Taken together, our results demonstrate a link between lactate metabolism and the mitochondria of fermenting mammalian cells.

Language

English (en)

Chair and Committee

Gary J. Patti

Committee Members

Jacob Schaefer, Liviu Mirica, Richard Gross, Brian Finck

Comments

Permanent URL: http://dx.doi.org/doi:10.7936/K7M61HN0

Available for download on Saturday, August 15, 2116

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