This study quantifies uptake of a fluorescent
glucose analog, (2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose) (2-NBDG), in a large panel of
breast cancer cells and demonstrates potential to monitor changes in glycolysis caused by anticancer and endocrine
therapies. Expressions of
glucose transporter (GLUT 1) and
hexokinase (HK I), which phosphorylates
2-NBDG, were measured via western blot in two normal mammary epithelial and eight
breast cancer cell lines of varying
biological subtype. Fluorescence intensity of each cell line labeled with 100 lM
2-NBDG for 20 min or unlabeled control was quantified. A subset of
cancer cells was treated with anticancer and endocrine
therapies, and
2-NBDG fluorescence changes were measured. Expression of GLUT 1 was necessary for uptake of
2-NBDG, as demonstrated by lack of
2-NBDG uptake in normal human mammary epithelial cells (HMECs). GLUT 1 expression and
2-NBDG uptake was ubiquitous among all
breast cancer lines. Reduction and stimulation of
2-NBDG uptake was demonstrated by perturbation with
anticancer agents,
lonidamine (LND), and a-cyano-hydroxycinnamate (a-Cinn), respectively. LND directly inhibits HK and significantly reduced
2-NBDG fluorescence in a subset of two
breast cancer cell lines. Conversely, when cells were treated with a-Cinn, a
drug used to increase glycolysis,
2-NBDG uptake was increased. Furthermore,
tamoxifen (tam), a common endocrine
therapy, was administered to
estrogen receptor positive and negative (ER?/-) breast cells and demonstrated a decreased
2-NBDG uptake in ER? cells, reflecting a decrease in glycolysis. Results indicate that
2-NBDG uptake can be used to measure changes in glycolysis and has potential for use in early
drug development.