The Interface of Tumour-Associated Macrophages with Dying Cancer Cells in Immuno-Oncology

Cells. 2022 Dec 2;11(23):3890. doi: 10.3390/cells11233890.

Abstract

Tumour-associated macrophages (TAMs) are essential players in the tumour microenvironment (TME) and modulate various pro-tumorigenic functions such as immunosuppression, angiogenesis, cancer cell proliferation, invasion and metastasis, along with resistance to anti-cancer therapies. TAMs also mediate important anti-tumour functions and can clear dying cancer cells via efferocytosis. Thus, not surprisingly, TAMs exhibit heterogeneous activities and functional plasticity depending on the type and context of cancer cell death that they are faced with. This ultimately governs both the pro-tumorigenic and anti-tumorigenic activity of TAMs, making the interface between TAMs and dying cancer cells very important for modulating cancer growth and the efficacy of chemo-radiotherapy or immunotherapy. In this review, we discuss the interface of TAMs with cancer cell death from the perspectives of cell death pathways, TME-driven variations, TAM heterogeneity and cell-death-inducing anti-cancer therapies. We believe that a better understanding of how dying cancer cells influence TAMs can lead to improved combinatorial anti-cancer therapies, especially in combination with TAM-targeting immunotherapies.

Keywords: TAM heterogeneity; apoptosis macrophage targeting; cancer therapy; chemotherapy; immunogenic cell death; immunotherapy; macrophages; radiotherapy; tumour microenvironment.

Publication types

  • Review

MeSH terms

  • Humans
  • Immunotherapy
  • Macrophages / metabolism
  • Neoplasms* / metabolism
  • Tumor Microenvironment
  • Tumor-Associated Macrophages*

Grants and funding

Research in ADG lab is supported by Research Foundation Flanders (FWO) (Fundamental Research Grant, G0B4620N; Excellence of Science/EOS grant, 30837538, for ‘DECODE’ consortium), KU Leuven (C1 grant, C14/19/098; C3 grant, C3/21/037; and POR award funds, POR/16/040), Kom op Tegen Kanker (KOTK/2018/11509/1; and KOTK/2019/11955/1) and VLIR-UOS (iBOF grant, iBOF/21/048, for ‘MIMICRY’ consortium to ADG). JS is funded by Kom op tegen Kanker (Stand up to Cancer), the Flemish cancer society via Emmanuel van der Schueren (EvDS) PhD fellowship (projectID: 12699). IV and RSL are supported by FWO-SB PhD Fellowship (1S06821N and 1S44123N). DMB is supported by KU Leuven’s Postdoctoral mandate grant (PDMT1/21/032), and FWO senior postdoctoral fellowship (1279223N).