Altered metabolism is a poorly understood feature of tumors that holds great promise for improved cancer therapy. However, success depends on understanding how metabolic regulation provides an advantage for tumor cells. Our understanding of how cancer cells meet their metabolic needs is based primarily on studies of cultured cells; and nutrient levels in vitro are significantly different from those experienced by tumor cells in vivo. Therefore, better models to study cancer metabolism in vivo are desperately needed. Recently, several studies have converged on serine metabolism as an important metabolic pathway that is dysregulated in cancer. Increased flux through the serine synthesis pathway branching from glycolysis is critical for cancer cell proliferation and tumor growth, and many key metabolic regulatory events promote an increase in new serine synthesis. However, increased serine pathway flux is necessary for some cancer cells even when serine is abundant, and why increased serine metabolism is important for cancer is not understood. The gene encoding the first enzyme of the serine synthesis pathway, PHGDH, is amplified in human tumors, including melanoma, and represents a way cancer cells increase serine production from glucose. Increased carbon flux into serine synthesis can be induced in cells by increasing PHGDH enzyme expression, and this presents the opportunity to determine if more serine synthesis can be a driver of malignancy. It also provides a tool to modulate serine synthesis and study the impact of this pathway on tumor metabolism. To better understand the role of serine synthesis in tumor biology, we propose in Aim 1 to generate a model of PHGDH-amplified cancer. Specifically, we will use a genetically engineered mouse model where PHGDH expression can be controlled in a temporal and tissue-specific manner to determine if increased PHGDH expression to levels found in human tumors promotes tumor initiation. For these experiments we will focus on melanoma, and evaluate the ability of PHGDH to cooperate with other genetic events associated with melanoma in humans. By evaluating tumors that form when PHGDH is expressed, we will also determine whether continued PHGDH expression and increased serine biosynthesis is required for tumor maintenance.
In Aim 2, we propose to study how increased serine biosynthesis influences metabolism to promote tumor growth in vivo. We will track the metabolism of stable isotope labeled nutrients in melanomas with and without PHGDH expression to determine how glucose-derived serine is used by these tumors, and understand the impact of increased serine biosynthesis on cancer metabolism. These studies will combine the use of unique animal models with current technology to interrogate metabolic pathway biochemistry and increase the understanding of tumor metabolism in vivo. They will also validate serine synthesis as a cancer drug target and aid efforts to target metabolism in patients.

Public Health Relevance

Altered metabolism represents a fundamental difference between cancer cells and normal cells that is not well understood. Of particular interest is the serine biosynthesis pathway as it has been implicated in many cancers and is the target of some successful cancer therapies. This application combines the use of unique animal models with current technology to interrogate metabolic pathways in animal tissues to determine how altered serine metabolism promotes the progression of endogenous tumors. This understanding is critical to improve the use of existing therapies that impact this pathway, and guide how to better target cancer metabolism to help patients

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21CA198028-01
Application #
8957151
Study Section
Special Emphasis Panel (ZCA1)
Program Officer
Spalholz, Barbara A
Project Start
2015-07-01
Project End
2017-06-30
Budget Start
2015-07-01
Budget End
2016-06-30
Support Year
1
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Massachusetts Institute of Technology
Department
Internal Medicine/Medicine
Type
Schools of Arts and Sciences
DUNS #
001425594
City
Cambridge
State
MA
Country
United States
Zip Code
Luengo, Alba; Gui, Dan Y; Vander Heiden, Matthew G (2017) Targeting Metabolism for Cancer Therapy. Cell Chem Biol 24:1161-1180
Vander Heiden, Matthew G; DeBerardinis, Ralph J (2017) Understanding the Intersections between Metabolism and Cancer Biology. Cell 168:657-669
Pikman, Yana; Puissant, Alexandre; Alexe, Gabriela et al. (2016) Targeting MTHFD2 in acute myeloid leukemia. J Exp Med 213:1285-306
Hosios, Aaron M; Hecht, Vivian C; Danai, Laura V et al. (2016) Amino Acids Rather than Glucose Account for the Majority of Cell Mass in Proliferating Mammalian Cells. Dev Cell 36:540-9
Pacold, Michael E; Brimacombe, Kyle R; Chan, Sze Ham et al. (2016) A PHGDH inhibitor reveals coordination of serine synthesis and one-carbon unit fate. Nat Chem Biol 12:452-8
Mattaini, Katherine R; Sullivan, Mark R; Vander Heiden, Matthew G (2016) The importance of serine metabolism in cancer. J Cell Biol 214:249-57