Metabolic programming and immune suppression in the tumor microenvironment.

Increased glucose metabolism and uptake are characteristic of many tumors and used clinically to diagnose and monitor cancer progression. In addition to cancer cells, the tumor microenvironment (TME) encompasses a wide range of stromal, innate, and adaptive immune cells. Cooperation and competition between these cell populations supports tumor proliferation, progression, metastasis, and immune evasion. Cellular heterogeneity leads to metabolic heterogeneity because metabolic programs within the tumor are dependent not only on the TME cellular composition but also on cell states, location, and nutrient availability. In addition to driving metabolic plasticity of cancer cells, altered nutrients and signals in the TME can lead to metabolic immune suppression of effector cells and promote regulatory immune cells. Here we discuss how metabolic programming of cells within the TME promotes tumor proliferation, progression, and metastasis. We also discuss how targeting metabolic heterogeneity may offer therapeutic opportunities to overcome immune suppression and augment immunotherapies. Arner and Rathmell discuss how metabolic programs within tumors depend not only on the tumor microenvironment (TME) cellular composition but also on cell states, location, and nutrient availability. Altered nutrient availability and signals in the TME lead to metabolic immune suppression, which drives immune evasion, tumor progression, and metastasis. Understanding and targeting metabolic heterogeneity within the TME may offer therapeutic opportunities to overcome immune suppression and augment immunotherapies. [ABSTRACT FROM AUTHOR]