Our major focus over the last five years has been to understand the role of the hexose transporter Glut1 in mammary tumorigenesis. We recently published that loss of Glut1 was sufficient to prevent mammary tumorigenesis induced by activated ErbB2. Most surprising was the observation was that loss of a single allele of Glut 1 was sufficient to block tumorigenesis; in other words, Glut1 was haplo-insufficient for tumorigenesis. This implies there is a threshold of glucose that is required for tumorigenesis, and a reduction in glucose uptake may be sufficient to block or prevent tumorigenesis. Using an in vitro model of ErbB2-dependent transformation of mammary epithelial cells, we showed that limiting glucose concentration to physiological levels prevented transformation of cells in three-dimensional cultures.
One logical conclusion of these studies is that tumor-initiating cells, or cancer stem cells, that lack Glut1 are not able to proliferate and undergo apoptosis. To address this hypothesis, we have labelled tumor-initiating cells that express ErbB2 and Cre recombinase (both are co-expressed by the NIC transgene) by introducing a transgene in which expression of green fluorescent protein is prevented by the presence of a lox-stop-lox cassette (LSL); as a result of this second transgene all Cre-expressing tumor cells are GFP+. Using fluorescent-activated cell sorting with established cell surface markers (CD24 and CD29), we have been able to isolate populations of GFP-expressing cells that correspond to mature luminal cells, luminal progenitors, and basal progenitors. The identity of these different subpopulations was confirmed by RNA-Seq analysis. Both the luminal and basal progenitor cells that express activated ErbB2 are able to form tumors upon transplantation into immunodeficient mice. ErbB2 expressing basal and luminal progenitor cells that were GFP+ could be isolated from mammary glands of MMTV-NIC mice that contain one copy, or no copies of Glut1, implying that the tumor initiating cells (caner stem cells) are not lost from these mice. We are currently analyzing RNA –Seq data to determine the differences in gene profiles between cancer stem cells that vary in expression of Glut1. These studies should reveal how glucose metabolism alters gene expression and the biology of tumor cells.
Since diabetes and obesity promote breast cancer in humans, we wish to use our mouse models to determine the extent to which these conditions alter tumorigenesis in mice. In collaboration with Dr. Wellberg, who has developed a new model for diet-induced obesity and hyperglycemia, we want to determine whether hyperglycemia will promote tumorigenesis in mice lacking one allele of Glut1. Given that two-thirds of women are now overweight or obese, understanding how these conditions alters mammary tumorigenesis in mice addresses a significant health problem in the developed world.
Elizabeth A. Wellberg, Ph.D., Research Assistant Professor
1. M.C. Neville, S.M. Anderson, J.L. McManaman, T. M. Badger, M. Bunik, N. Contractor, T. Crume, D. Dabelea, S.M. Donovan, N. Forman, D.N. Frank, J.E. Friedman, J.B. German, A. Goldman, D. Hadsell, M. Hambidge, K. Hinde, N.D. Horseman, R.C. Hovey, E. Janoff, N. Krebs, C.B. Lebrilla, D.G. Lemay, P.S. MacLean, P. Meier, A. Morrow, J. Neu, L.A. Nommsen-Rivers, M. Rijnkels, V. Seewaldt, B.D. Shur, J. VanHouten, P. Williamson, 2012. “Lactation and Neonatal Nutrition: Defining and Refining the Critical Questions,” J. Mammary Gland Biology and Neoplasia 17 (2): 167-188. PMID 22752723.
2. Rudolph, M.C., N.K. Maluf, E.A. Wellberg, C.A. Johnson, R.C. Murphy, and S.M. Anderson, 2012. “Mammalian fatty acid synthase activity from crude lysates tracing (13)C-labelled substrates using gas chromatography-mass spectrometry.” Anal. Biochem. 428 (15): 158-166. PMID 22728958.
3. E.D. Giles, E.A. Wellberg, D.P. Astling, S.M. Anderson, A.D. Thor, S. Jindal, A.C. Tan, P.S. Schedin, and P.S. MacLean, 2012. “Obesity and overfeeding affecting both tumor and systemic metabolism activates the progesterone receptor to contribute to postmenopausal breast cancer.” Cancer Research 72 (24): 6490-6501. PMID 23222299.
4. R.O. Pereira, A.R. Wende, C. Olsen, J. Soto, T. Rawlings, Y. Zhu, S.M. Anderson, and E.D. Abel, 2013. “Inducible Overexpression of GLUT1 Prevents Mitochondrial Dysfunction and Attenuates Structural Remodeling in Pressure Overload but does not Prevent Left Ventricular Dysfunction.” J Am Heart Assoc. 2013 Sep 19;2(5):e000301. doi: 10.1161/JAHA. PMID 24052497
5. M.C. Neville, P. Webb, P. Ramanathan, M. Phistry, C. Pecorini, J. Monks, S.M. Anderson, P. MacLean, 2013. “The Insulin Receptor Plays an Important Role in Secretory Differentiation in the Mammary Gland.” American Journal of Physiology-Endocrinology and Metabolism 305 (9): E1103-1114. PMID: 23982156.
6. R. Wahdan-Alaswad, Z. Fan, S.M. Edgerton, B. Liu, X.-S. Deng, S. S. Arnadottir, J. Richer, S.M. Anderson, and A.D. Thor, 2013. “Glucose Promotes Breast Cancer Aggression and Reduces Metformin Efficacy.” Cell Cycle 12(24): 3759-3769. PMID:24107633.
7. J.W. Schmidt, B.L. Wehde, K. Sakamoto, A.A. Triplett, S.M. Anderson, P.N. Tsichlis, G. Leone and K.-U. Wagner, 2014. “Stat5 regulates the PI3-kinase/Akt1 pathway during mammary gland development and tumorigenesis.” Molecular and Cellular Biology 34 (7): 1363-1377. PMID 24469394.
8. S.M. Wie, T.S. Adwan, J. DeGregori, S.M. Anderson and M.E. Reyland, 2014. “Inhibiting tyrosine phosphorylation of PKC protects the salivary gland from radiation damage.” Journal of Biological Chemistry 289 (15): 10900-10908. PMID24569990
9. M.C. Rudolph, E.A. Wellberg, A.S. Lewis, A.L. Merz, N.K. Maluf, N.A. Serkova, and S.M. Anderson, 2014. Thyroid Hormone Responsive Protein Spot14 enhances catalysis of fatty acid synthase in lactating mammary epithelium.” Journal of Lipid Research 55 (6): 1052-1065. PMID 24771867.
10. A.N. Macintyre, V.A. Gerriets, A.G. Nichols, R.D. Michalek, M.C. Rudolph, D. Deoliveira D, S.M. Anderson, E.D. Abel, B.J. Chen, L.P. Hale, and J.C. Rathmell, 2014. The glucose transporter Glut1 is selectively essential for CD4 T cell activation and effector function. Cell Metab. 20(1):61-72. PMID: 24930970.
11. R. Wahdan-Alaswad*, D.R. Cochrane*, N.S. Spoelstra, E.N. Howe, S.M. Anderson, A.D. Thor and J.K. Richer, 2014. “Metformin-induced killing of triple negative breast cancer cells is mediated by reduction in fatty acid synthase via miRNA-193b.” Hormones and Cancer, Dec 5(6) 364-389. doi 10.1007/s12672-0188-8. PMID 25213330.
12. E.A. Wellberg, and S.M. Anderson, 2014. FASNating targets of metformin in breast cancer stem-like cells. Hormones and Cancer, Dec 5(6):358-362. Doi: 1007/s12672-114-0198-6. PMID 25172609.
13. E.A. Wellberg, M.C. Rudolph, A.S. Lewis, N. Padila-Just, P. Jedlicka and S.M. Anderson, 2014. “Modulation of tumor fatty acids, through overexpression or loss of thyroid hormone responsive protein spot14 is associated with altered growth and metastasis.” Breast Cancer Research 16:490 (December 4, 2014). PMID: 25472762.
14. R.E. Heinz, M.C. Rudolph, P. Ramanathan, N.S. Spoelstra, K.T. Butterfield, P.G. Webb, B.L. Babbs, H. Gao, S. Chen, M.A. Gordon, S.M. Anderson, M.C. Neville, H. Gu and J. K. Richer, 2016. “Constitutive expression of microRNA-150 in mammary epithelium suppresses secretory activation and impairs de novo lipogenesis.” Development 143(22):4236-4248. PMID 27729410.
15. E.A. Wellberg, S. Johnson, K. Terrell, A.S. Lewis, J. Finlay-Schutz, C.A. Sartorius, E. D. Abel, W.J. Muller, and S.M. Anderson, 2016. “The hexose transporter GLUT1 is required for ErbB2-induced mammary tumorigenesis. Breast Cancer Res. 18:131. DOI 10.1186/s13058-016-0795-0 Published online: December 20, 2016
16. L.A. Checkley, M.C. Rudolph, E.A. Wellberg, E.D. Giles, R. Wahdan-Alaswad, J. Houck, S.M. Edgerton, A.D. Thor, P.S. Schedin, S.M. Anderson, and P.S. MacLean, 2017. Metformin Accumulation Correlates with Organic Cation Transporter 2 Protein Expression and Predicts Mammary Tumor Regression in Vivo”. Cancer Prev. Res. Feb 2. doi: 10.1158/1940-6207.CAPR-16-0211-T. [Epub ahead of print]. PMID: 28154203
17. E.A. Wellberg, L.A. Checkley, E.D. Giles, S.J. Johnson, R, Oljira, R. Wahdan-Alaswad, R.M. Foright, G. Dooley, S.M. Edgerton, S. Jindal, G.C. Johnson, J.K. Richer, P. Kabos, A.D. Thor, P. Schedin, P.S. MacLean, and S.M. Anderson, 2017. "The Androgen Receptor supports tumor progression after the loss of ovarian function in a preclinical model of obesity and breast cancer.” Hormones and Cancer 8 (5,6):269-285.