Functional states of myeloid cells in cancer

Myeloid cells, comprised of macrophages, dendritic cells, monocytes, and granulocytes, represent a major component of the tumor microenvironment (TME) and are critically involved in regulation of tumor progres-sion and metastasis. In recent years, single-cell omics technologies have identified multiple phenotypically distinct subpopulations. In this review, we discuss recent data and concepts suggesting that the biology of myeloid cells is largely defined by a very limited number of functional states that transcend the narrowly defined cell populations. These functional states are primarily centered around classical and pathological states of activation, with the latter state commonly defined as myeloid-derived suppressor cells. We discuss the concept that lipid peroxidation of myeloid cells represents a major mechanism that governs their patho-logical state of activation in the TME. Lipid peroxidation is associated with ferroptosis mediating suppressive activity of these cells and thus could be considered an attractive target for therapeutic intervention.

Automated summary

This review discusses the classification of myeloid cells using single-cell omics technologies in the tumor microenvironment (TME). It suggests that the biology of myeloid cells is primarily determined by a limited number of functional states, including classical and pathological activation states. The article also explores the relationship between lipid peroxidation of myeloid cells and their activation state in the TME, highlighting its potential as a therapeutic target.