The IDO enzyme produced by cancer cells inhibits the anti-cancer immune response and has nothing to do with cancer tryptophan metabolism

In a new study, researchers from Northwestern University found that many cancers produce an enzyme called IDO (indoleamine 2,3-dioxygenase 1, indoleamine 2,3-dioxygenase 1).

In addition to participating in tryptophan metabolism, IDO can also enhance the immunosuppressive factors of the complement immune system

Many difficult-to-treat cancers, including glioblastoma, prostate cancer, and pancreatic cancer, show high levels of IDO expression

Many clinical trials that use drug-based IDO enzyme inhibitors in combination with immunotherapy have shown that there is no improvement in patient survival compared with immunotherapy alone

These authors found that IDO, regardless of its ability to metabolize tryptophan, is related to the decreased survival rate of experimental animals with brain tumors and increased accumulation of immunosuppressive cells

When they were studying the role of IDO in tumor cells, a special approach caught their attention: the complement cascade

Glioblastoma

Note: The original text has been deleted

Reference materials:

Lijie Zhai et al.