Bode, Barrie P.
Ph.D. (Doctor of Philosophy)
Department of Biological Sciences
Biology; Molecular biology; Oncology
Human hepatocellular carcinoma (HCC) is an increasing threat worldwide due to cirrhosis of the liver developing from viral hepatitis and non-alcoholic steatohepatitis (NASH). Breast cancer is the second leading cause of cancer death in American women, with the most intractable type classified as triple negative. Both cancers depend on glutamine as the major oxidizable substrate for tumor growth, therefore, identification of glutamine transporters and transporter activity is of vital importance in the development of treatment options. It is well documented that ASCT2 is the major glutamine transporter in both cancers but little is known regarding the relative amounts of additional glutamine transporters that operate in these primary and metastatic tumors. Studies using thirteen HCC cell lines investigated eight glutamine transporters via gene expression studies, Western blot assays, and functional analysis. None of the studies, however, incorporated the tumor microenvironment (the stroma), the vital interacting feature of actual tumor growth. In vivo studies were then completed using the EMT6 cell line, a murine mammary carcinoma from a BALB/c laboratory mouse with characteristics of triple negative human breast cancer (TNBC). To distinguish cancer cells from stromal cells, EMT6 was transfected with antibiotic-selective green fluorescent protein (GFP) prior to injection into the mammary fat pads of the genetically identical BALB/c mouse. In vitro results showed that HCC and EMT6 cell lines were glutamine dependent, obtained the majority of glutamine via ASCT2, and used several transporters that were differentially expressed, though transporter activities, cognate mRNA, and protein expression levels were discordant. In vivo mammary carcinoma results showed an increase in all expression levels of transporters, receptors, and enzymes compared to the In vitro EMT6 cell line. EMT6-GFP transfected tumor cells nearly universally induced greater mRNA expression compared to unmodified tumor cells used as a control. The results of this project highlighted the complex and layered regulation between gene expression and physiological activity In vitro , and the changes of mRNA expression In vivo due to both stromal involvement and the effects of antibiotic-selective transfection.
Kron, Clare, "Glutamine transporters in human hepatocellular carcinoma and in the EMT6 mammary tumor and adjacent stroma in the syngeneic BALB/c mouse model" (2017). Graduate Research Theses & Dissertations. 3299.
xiii, 141 pages
Northern Illinois University
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