Date Approved

2016

Document Type

Thesis

Degree Name

Master of Science in Cellular and Molecular Biology

Department

Molecular Biology

College

Graduate School of Biomedical Sciences

First Advisor

Catherine Neary, PhD

Committee Member 1

Salvatore Caradonna, PhD

Committee Member 2

Subhasis Biswas, PhD

Subject(s)

Hexokinase; HeLa Cells; AMP-Activated Protein Kinases; Immunohistochemistry; Glycolysis; Repressor Proteins; Neoplasms

Disciplines

Cancer Biology | Cell Biology | Chemical and Pharmacologic Phenomena | Laboratory and Basic Science Research | Medical Cell Biology | Medical Molecular Biology | Neoplasms

Abstract

In order for a cancer cell to thrive, it must alter its metabolism to produce the energy needed for rapid growth. Cells accomplish this by the Warburg Effect, or switching metabolism to aerobic glycolysis, where a cell can rapidly break down sugar into ATP, lactic acid and additional byproducts. Hexokinase 2, the enzyme that catalyzes the first committed step of glycolysis, may also be upregulated in cancer cells to increase glucose breakdown. Similar proteins for metabolism are found in both S. cerevisiae and mammalian cells. S. cerevisiae regulates metabolism through glucose repression, by Snf1 (mammalian homolog: AMPK) activation, which aids in HK2 translocation to the nucleus. Once in the nucleus, HK2 acts as a transcriptional repressor of various metabolic proteins. Previous research has shown detachment from the mitochondria and translocation of HK2 to the nucleus with the addition of potential AMPK activating drugs in HeLa cervical cancer cells. If a mechanism similar to the yeast glucose repression system functions in mammalian cells, a similar relationship between AMPK activation and HK2 localization may exist. HK2 localization was observed through immunocytochemistry and western blotting in HeLa cells treated with AMPK activators, either AICAR or metformin, as well as AMPK inhibitors, Compound C and siRNA. No correlation between AMPK activation and HK2 translocation was observed; however AMPK activation continually led to changes in HK2 aggregation and attachment. A better understanding of the interaction between AMPK and mitochondrial-bound HK2 could lead to insights into the regulation of glycolysis.

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