Targeting amino acid-metabolizing enzymes for cancer immunotherapy

Area of Science:

• Immunology and Cancer Biology
• Metabolic pathways in cancer
• Tumor microenvironment

Background:

• Cancer cells exploit immune escape mechanisms to evade host immune responses.
• Upregulation of amino acid-metabolizing enzymes by cancer cells or tumor-infiltrating cells is a key immune evasion strategy.
• Amino acid availability and their metabolites critically influence immune cell function and the anti-tumor response.

Purpose of the Study:

• To review the involvement of specific amino acid-metabolizing enzymes in cancer immune evasion.
• To discuss the impact of these enzymes and their metabolites on the anti-tumor immune response.
• To summarize progress in targeting these enzymes for cancer immunotherapy.

Main Methods:

• Literature review of studies investigating amino acid-metabolizing enzymes in cancer.
• Analysis of the role of glutaminase 1 (GLS1), arginase 1 (ARG1), inducible nitric oxide synthase (iNOS), indoleamine 2,3-dioxygenase 1 (IDO1), tryptophan 2,3-dioxygenase (TDO), and interleukin 4 induced 1 (IL4I1).
• Summary of preclinical and clinical data on inhibitors targeting these enzymes.

Main Results:

• These enzymes contribute to tumor immune escape by depleting essential amino acids or producing immunosuppressive metabolites.
• Inhibition of these enzymes demonstrates potential in restoring anti-tumor immunity.
• Preclinical and clinical studies show promise for enzyme-targeted immunotherapies.

Conclusions:

• Targeting amino acid-metabolizing enzymes represents a viable strategy for cancer immunotherapy.
• Further development of inhibitors for GLS1, ARG1, iNOS, IDO1, TDO, and IL4I1 is warranted.
• Modulating tumor amino acid metabolism can enhance anti-tumor immune responses.