Selective glutamine metabolism inhibition in tumor cells improves antitumor T lymphocyte activity in triple-negative breast cancer
Deanna N. Edwards, … , Mark R. Boothby, Jin Chen
Deanna N. Edwards, … , Mark R. Boothby, Jin Chen
Published December 15, 2020
Citation Information: J Clin Invest. 2021;131(4):e140100. https://doi.org/10.1172/JCI140100.
View: Text | PDF
Research Article Oncology

Selective glutamine metabolism inhibition in tumor cells improves antitumor T lymphocyte activity in triple-negative breast cancer

Abstract

Rapidly proliferating tumor and immune cells need metabolic programs that support energy and biomass production. The amino acid glutamine is consumed by effector T cells and glutamine-addicted triple-negative breast cancer (TNBC) cells, suggesting that a metabolic competition for glutamine may exist within the tumor microenvironment, potentially serving as a therapeutic intervention strategy. Here, we report that there is an inverse correlation between glutamine metabolic genes and markers of T cell–mediated cytotoxicity in human basal-like breast cancer (BLBC) patient data sets, with increased glutamine metabolism and decreased T cell cytotoxicity associated with poor survival. We found that tumor cell–specific loss of glutaminase (GLS), a key enzyme for glutamine metabolism, improved antitumor T cell activation in both a spontaneous mouse TNBC model and orthotopic grafts. The glutamine transporter inhibitor V-9302 selectively blocked glutamine uptake by TNBC cells but not CD8+ T cells, driving synthesis of glutathione, a major cellular antioxidant, to improve CD8+ T cell effector function. We propose a “glutamine steal” scenario, in which cancer cells deprive tumor-infiltrating lymphocytes of needed glutamine, thus impairing antitumor immune responses. Therefore, tumor-selective targeting of glutamine metabolism may be a promising therapeutic strategy in TNBC.

Authors

Deanna N. Edwards, Verra M. Ngwa, Ariel L. Raybuck, Shan Wang, Yoonha Hwang, Laura C. Kim, Sung Hoon Cho, Yeeun Paik, Qingfei Wang, Siyuan Zhang, H. Charles Manning, Jeffrey C. Rathmell, Rebecca S. Cook, Mark R. Boothby, Jin Chen

×

Figure 5

The glutamine transporter inhibitor V-9302 suppresses tumor growth and increases T lymphocyte activation in a model of TNBC.

Options: View larger image (or click on image) Download as PowerPoint
The glutamine transporter inhibitor V-9302 suppresses tumor growth and i...
E0771 cells (2.5 × 105) were bilaterally injected into the number 4 mammary fat pads of female C57BL/6 mice (Taconic). Beginning on day 11, mice were treated with vehicle (DMSO, red) or 50 mg/kg V-9302 (blue) daily for 5 days. (A) Tumor volume was measured over time. Arrow indicates beginning of treatment. P < 1 × 10–15 by 2-way ANOVA. n = 9–10 mice per group. (B) Average tumor mass per mouse at harvest. P = 0.0060 by unpaired Student’s t test. n = 9–10 mice per group. (C) Immunofluorescence of tumor sections for Ki67 (top) or cleaved caspase-3 (bottom), both red. Nuclei were stained with DAPI (blue). Scale bars: 20 μm. Ki67+, cleaved caspase-3+, and nuclei were averaged from 3 fields of view. Unpaired Student’s t test: P = 0.283 (Ki67), P = 0.023 (cleaved caspase-3). (D) Flow cytometric analyses of CD4+ (left) or CD8+ (right) T cells, plotted as a percentage of CD45+ immune cells, in vehicle- (red) or V-9302–treated (blue) tumors. Unpaired Student’s t test: P = 0.023 (CD4+), P = 0.340 (CD8+). n = 5 mice per group. (E) Immunohistochemistry of CD8a (brown) from vehicle- or V-9302–treated (50 mg/kg) tumors. Nuclei were stained with hematoxylin (blue). Edge (black) is considered <500 μm (denoted by solid line) from tumor margin, core (red) is >500 μm. Scale bars: 500 μm and 50 μm for expanded and enlarged images, respectively. CD8+ cells (denoted by arrows) were averaged from 3 fields of view and normalized to field-of-view area. P = 0.019 by unpaired Student’s t test. n = 3 mice per group. (F–K) Flow cytometric analyses of (F) CD8+GZMB+, (G) CD8+CD107a+, (H) CD8+IFN-γ+, (I) CD4+IFN-γ+, (J) CD4+IL-4+, and (K) CD4+FoxP3+CD25+CD127loCD45+CD3+ T cells in vehicle- (red) or V-9302–treated (blue) tumors. Unpaired Student’s t test: P = 0.014 (CD8+GZMB+), P = 0.047 (CD8+CD107a+), P = 0.007 (CD8+IFN-γ+), P = 0.0021 (CD4+IFN-γ+), P = 0.057 (CD4+IL-4+), P = 0.034 (CD4+FoxP3+CD25+CD127lo). n = 3–8 mice per group. *P < 0.05, **P < 0.01, ****P < 0.001.