Macrophage Polarization in the Development and Progression of Ovarian Cancers: An Overview

Abstract

Ovarian cancer is the most lethal gynecological malignancy worldwide. Most patients are diagnosed at late stages because of atypical symptoms and the lack of effective early diagnostic measures. The mechanisms underlying the oncogenesis and development of ovarian cancer are not clear. Macrophages, immune cells derived from the innate immune system, have two states of polarization (M1 and M2) that develop in response to different stimuli. The polarization and differentiation of macrophages into the cancer-inhibiting M1 and cancer-promoting M2 types represent the two states of macrophages in the tumor microenvironment. The interaction of polarized macrophages with cancer cells plays a crucial role in a variety of cancers. However, the effects of macrophage M1/M2 polarization on ovarian cancer have not yet been systematically and fully discussed. In this review, we discuss not only the occurrence, development and influences of macrophage polarization but also the association between macrophage polarization and ovarian cancer. The polarization of macrophages into the M1 and M2 phenotypes plays a pivotal role in ovarian cancer initiation, progression, and metastasis, and provides targets for macrophage-centered treatment in the cancer microenvironment for ovarian cancer therapy. We also addressed the regulation of macrophage polarization in ovarian cancer via noncoding RNAs, exosomes, and epigenetics.

Inflammatory Responses during Tumour Initiation: From Zebrafish Transgenic Models of Cancer to Evidence from Mouse and Man

“…The expression of pro-inflammatory cytokines by macrophages and neutrophils in response to tumour initiation in zebrafish studies corresponds with the hypothesis that tumour-associated inflammation begins with a pro-inflammatory response, which becomes progressively more anti-inflammatory throughout the course of tumourigenesis [86,87,[198][199][200][201]. This phenomenon mimics the inflammatory wound response; in both zebrafish and mammals the wound response is characterised by early M1/N1 activation followed by a switch to M2/N2 activation states, the latter of which promotes tissue repair and resolution [51,[202][203][204].…”

Inflammatory Responses during Tumour Initiation: From Zebrafish Transgenic Models of Cancer to Evidence from Mouse and Man

“…The expression of pro-inflammatory cytokines by macrophages and neutrophils in response to tumour initiation in zebrafish studies corresponds with the hypothesis that tumour associated inflammation begins with a pro-inflammatory response, which becomes progressively more anti-inflammatory throughout the course of tumourigenesis [68,69,[181][182][183][184]. This phenomenon mimics the wound response which, in both zebrafish and mammals, is characterised by early M1/N1 activation followed by a switch to M2/N2 activation states that promote tissue repair and resolution [43,[185][186][187], with the exception that tumours provoke a sustained response, thus creating a positive-feedback cycle of non-resolving inflammation and tissue repair [181].…”

Profiles of Immune Infiltration in Bladder Cancer and its Clinical Significance: an Integrative Genomic Analysis

“…Cluster 1 was characterized by the increased infiltration of M2 macrophages and CD4 memory T cells. M2 macrophages play a role in antiinflammatory processes, tissue repair and remodeling, the immune regulation process, parasite clearance, and the tumor promotion process [21]. The immunosuppressive factors released by M2 macrophages may support immune evasion in bladder cancer.…”